Silicon carbide offers distinct advantages in the field of power electronic devices. However, manufacturing processes remain a significant barrier to its widespread adoption. Polycrystalline SiC is less expensive and easier to produce than single crystal. But stabilizing and controlling its performance are critical challenges that must be addressed urgently. Due to its material properties and excellent performance in applications, 3C-SiC is gaining increasing attention in research. This article presents the electrical and material properties of a series of polycrystalline 3C-SiC samples and investigates their interrelationship. The samples were examined using TEM, which confirmed their polycrystalline structure. Combined with XRD and Raman spectroscopy, the grain orientations within the samples were analyzed, and the presence of stress was verified. EBSD was employed to statistically examine the grain structure and size across samples. For samples with similar doping levels, grain size is the most influential factor in determining electrical characteristics. Further EBSD measurements reveal the relationship between resistivity and grain size as log(ρ) = ?1.93 + 8.67/d. These findings provide a foundation for the quantitative control and application of polycrystalline 3C-SiC. This work offers theoretical evidence for optimizing the performance tuning of 3C-SiC ceramics and enhancing their effectiveness in electronic applications.

In this study, we present the fabrication of vertical SnO/β-Ga2O3 heterojunction diode (HJD) via radio frequency (RF) reactive magnetron sputtering. The valence and conduction band offsets between β-Ga2O3 and SnO are determined to be 2.65 and 0.75 eV, respectively, through X-ray photoelectron spectroscopy, showing a type-Ⅱ band alignment. Compared to its Schottky barrier diode (SBD) counterpart, the HJD presents a comparable specific ON-resistances (Ron,sp) of 2.8 mΩ·cm2 and lower reverse leakage current (IR), leading to an enhanced reverse blocking characteristics with breakdown voltage (BV) of 1675 V and power figure of merit (PFOM) of 1.0 GW/cm2. This demonstrates the high quality of the SnO/β-Ga2O3 heterojunction interface. Silvaco TCAD simulation further reveals that electric field crowding at the edge of anode for the SBD was greatly depressed by the introduction of SnO film, revealing the potential application of SnO/β-Ga2O3 heterojunction in the future β-Ga2O3-based power devices.

Doping plays a pivotal role in enhancing the performance of organic semiconductors (OSCs) for advanced optoelectronic and thermoelectric applications. In this study, we systematically investigated the doping performance and applicability of the ionic dopant 4-isopropyl-4′-methyldiphenyliodonium tetrakis(penta-fluorophenyl-borate) (DPI-TPFB) as a p-dopant for OSCs. Using the p-type OSC PBBT-2T as a model system, we demonstrated that DPI-TPFB shows significant doping effect, as confirmed by ESR spectra, ultraviolet?visible?near-infrared (UV?vis?NIR) absorption, and work function analysis, and enhances the electronic conductivity of PBBT-2T films by over four orders of magnitude. Furthermore, DPI-TPFB exhibited broad doping applicability, effectively doping various p-type OSCs and even imparting p-type characteristics to the n-type OSC N2200, transforming its intrinsic n-type behavior into p-type. The application of DPI-TPFB-doped PBBT-2T films in organic thermoelectric devices (OTEs) was also explored, achieving a power factor of approximately 10 μW?m?1?K?2. These findings highlight the potential of DPI-TPFB as a versatile and efficient dopant for integration into organic optoelectronic and thermoelectric devices.

Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum, distinguished by their robust penetration capabilities and non-ionizing nature. These wavebands offer the potential for achieving high-resolution and non-destructive detection methodologies, thereby possessing considerable research significance across diverse domains including communication technologies, biomedical applications, and security screening systems. Two-dimensional materials, owing to their distinctive optoelectronic attributes, have found widespread application in photodetection endeavors. Nonetheless, their efficacy diminishes when tasked with detecting lower photon energies. Furthermore, as the landscape of device integration evolves, two-dimensional materials struggle to align with the stringent demands for device superior performance. Topological materials, with their topologically protected electronic states and non-trivial topological invariants, exhibit quantum anomalous Hall effects and ultra-high carrier mobility, providing a new approach for seeking photosensitive materials for infrared and terahertz photodetectors. This article introduces various types of topological materials and their properties, followed by an explanation of the detection mechanism and performance parameters of photodetectors. Finally, it summarizes the current research status of near-infrared to far-infrared photodetectors and terahertz photodetectors based on topological materials, discussing the challenges faced and future prospects in their development.

A 4H-SiC superjunction (SJ) MOSFET (SJMOS) with integrated high-K gate dielectric and split gate (HKSG-SJMOS) is proposed in this paper. The key features of HKSG-SJMOS involve the utilization of high-K (HK) dielectric as the gate dielectric, which surrounds the source-connected split gate (SG) and metal gate. The high-K gate dielectric optimizes the electric field distribution within the drift region, creating a low-resistance conductive channel. This enhancement leads to an increase in the breakdown voltage (BV) and a reduction in the specific on resistance (Ron,sp). The introduction of split gate surrounded by high-K dielectric reduces the gate?drain capacitance (Cgd) and gate?drain charge (Qgd), which improves the switching characteristics. The simulation results indicate that compared to conventional 4H-SiC SJMOS, the HKSG-SJMOS exhibits a 110.5% enhancement in figure of merit (FOM, FOM = BV2/Ron,sp), a 93.6% reduction in the high frequency figure of merit (HFFOM) of Ron,sp·Cgd, and reductions in turn-on loss (Eon) and turn-off loss (Eoff) by 38.3% and 31.6%, respectively. Furthermore, the reverse recovery characteristics of HKSG-SJMOS has also discussed, revealing superior performance compared to conventional 4H-SiC SJMOS.

This brief presents a cryogenic voltage reference circuit designed to operate effectively across a wide temperature range from 30 to 300 K. A key feature of the proposed design is utilizing a current subtraction technique for temperature compensation of the reference current, avoiding the deployment of bipolar transistors to reduce area and power consumption. Implemented with a 0.18-μm CMOS process, the circuit achieves a temperature coefficient (TC) of 67.5 ppm/K, which was not achieved in previous works. The design can also attain a power supply rejection (PSR) of 58 dB at 10 kHz. Meanwhile, the average reference voltage is 1.2 V within a 1.6% 3σ-accuracy spread. Additionally, the design is characterized by a minimal power dissipation of 1 μW at 30 K and a compact chip area of 0.0035 mm2.

The radiation-sensitive field effect transistors (RADFET) radiation dosimeter is a type of radiation detector based on the total dose effects of the p-channel metal?oxide?semiconductor (PMOS) transistor. The RADFET chip was fabricated in United Microelectronics Center 8-inch process with a six-layer photomask. The chip including two identical PMOS transistors, occupies a size of 610 μm × 610 μm. Each PMOS has a W/L ratio of 300 μm/50 μm, and a 400 nm thick gate oxide, which is formed by a dry-wet-dry oxygen process. The wet oxygen-formed gate oxide with more traps can capture more holes during irradiation, thus significantly changing the PMOS threshold voltage. Pre-irradiation measurement results from ten test chips show that the initial average voltage of the PMOS is 1.961 V with a dispersion of 5.7%. The irradiation experiment is conducted in a cobalt source facility with a dose rate of 50 rad(Si)/s. During irradiation, a constant current source circuit of 10 μA was connected to monitoring the shift in threshold voltage under different total dose. When the total dose is 100 krad(Si), the shift in threshold voltage was approximately 1.37 V, which demonstrates that an excellent radiation function was achieved.

Besides the common short-channel effect (SCE) of threshold voltage (Vth) roll-off during the channel length (L) downscaling of InGaZnO (IGZO) thin-film transistors (TFTs), an opposite Vth roll-up was reported in this work. Both roll-off and roll-up effects of Vth were comparatively investigated on IGZO transistors with varied gate insulator (GI), source/drain (S/D), and device architecture. For IGZO transistors with thinner GI, the SCE was attenuated due to the enhanced gate controllability over the variation of channel carrier concentration, while the Vth roll-up became more noteworthy. The latter was found to depend on the relative ratio of S/D series resistance (RSD) over channel resistance (RCH), as verified on transistors with different S/D. Thus, an ideal S/D engineering with small RSD but weak dopant diffusion is highly expected during the downscaling of L and GI in IGZO transistors.

In this paper, a high-gain inductorless LNA (low-noise amplifier) compatible with multiple communication protocols from 0.1 to 5.1 GHz is proposed. A composite resistor?capacitor feedback structure is employed to achieve a wide bandwidth matching range and good gain flatness. A second stage with a Darlington pair is used to increase the overall gain of the amplifier, while the gain of the first stage is reduced to reduce the overall noise. The amplifier is based on a 0.25 μm SiGe BiCMOS process, and thanks to the inductorless circuit structure, the core circuit area is only 0.03 mm2. Test results show that the lowest noise figure (NF) in the operating band is 1.99 dB, the power gain reaches 29.7 dB, the S11 and S22 are less than ?10 dB, the S12 is less than ?30 dB, the IIP3 is 0.81dBm, and the OP1dB is 10.27 dBm. The operating current is 31.18 mA at 3.8 V supply.

The transition of cobalt ions located at tetrahedral sites will produce strong absorption in the visible and near-infrared regions, and is expected to work in a passively Q-switched solid-state laser at the eye-safe wavelength of 1.5 μm. In this study, Co2+ ions were introduced into the wide bandgap semiconductor material ZnGa2O4, and large-sized and high-quality Co2+-doped ZnGa2O4 crystals with a volume of about 20 cm3 were grown using the vertical gradient freeze (VGF) method. Crystal structure and optical properties were analyzed using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and absorption spectroscopy. XRD results show that the Co2+-doped ZnGa2O4 crystal has a pure spinel phase without impurity phases and the rocking curve full width at half maximum (FWHM) is only 58 arcsec. The concentration of Co2+ in Co2+-doped ZnGa2O4 crystals was determined to be 0.2 at.% by the energy dispersive X-ray spectroscopy. The optical band gap of Co2+-doped ZnGa2O4 crystals is 4.44 eV. The optical absorption spectrum for Co2+-doped ZnGa2O4 reveals a prominent visible absorption band within 550?670 nm and a wide absorption band spanning from 1100 to 1700 nm. This suggests that the Co2+ ions have substituted the Zn2+ ions, which are typically tetrahedrally coordinated, within the lattice structure of ZnGa2O4. The visible region's absorption peak and the near-infrared broad absorption band are ascribed to the 4A2(4F) → 4T1(4P) and 4A2(4F) →4T1(4F) transitions, respectively. The optimal ground state absorption cross section was determined to be 3.07 × 10?19 cm2 in ZnGa2O4, a value that is comparatively large within the context of similar materials. This finding suggests that ZnGa2O4 is a promising candidate for use in near-infrared passive Q-switched solid-state lasers.

Graphene has garnered significant attention in photodetection due to its exceptional optical, electrical, mechanical, and thermal properties. However, the practical application of two-dimensional (2D) graphene in optoelectronic fields is limited by its weak light absorption (only 2.3%) and zero bandgap characteristics. Increasing light absorption is a critical scientific challenge for developing high-performance graphene-based photodetectors. Three-dimensional (3D) graphene comprises vertically grown stacked 2D-graphene layers and features a distinctive porous structure. Unlike 2D-graphene, 3D-graphene offers a larger specific surface area, improved electrochemical activity, and high chemical stability, making it a promising material for optoelectronic detection. Importantly, 3D-graphene has an optical microcavity structure that enhances light absorption through interaction with incoming light. This paper systematically reviews and analyzes the current research status and challenges of 3D-graphene-based photodetectors, aiming to explore feasible development paths for these devices and promote their industrial application.

With the rapid advancement of 5G communication technology, increasingly stringent demands are placed on the performance and functionality of phase change switches. Given that RF and microwave signals exhibit characteristics of high frequency, high speed, and high precision, it is imperative for phase change switches to possess fast, accurate, and reliable switching capabilities. Moreover, wafer-level compositional homogeneity and resistivity uniformity during semiconductor manufacturing are crucial for ensuring the yield and reliability of RF switches. By controlling magnetron sputter of GeTe through from four key parameters (pressure, power, Ar flow, and post-annealing) and incorporating elemental proportional compensation in the target, we achieved effective modulation over GeTe uniformity. Finally, we successfully demonstrated the process integration of GeTe phase-change RF switches on 6-inch scaled wafers.

The emergence of cesium lead halide perovskite materials stable at air opened new prospects for the optoelectronic industry. In this work we present an approach to fabricating a flexible green perovskite light-emitting electrochemical cell (PeLEC) with a CsPbBr3 perovskite active layer using a highly-ordered silicon nanowire (Si NW) array as a distributed electrode integrated within a thin polydimethylsiloxane film (PDMS). Numerical simulations reveal that Si NWs-based distributed electrode aids the improvement of carrier injection into the perovskite layer with an increased thickness and, therefore, the enhancement of light-emitting performance. The X-ray diffraction study shows that the perovskite layer synthesized on the PDMS membrane with Si NWs has a similar crystal structure to the ones synthesized on planar Si wafers. We perform a comparative analysis of the light-emitting devices’ properties fabricated on rigid silicon substrates and flexible Si NW-based membranes released from substrates. Due to possible potential barriers in a flexible PeLEC between the bottom electrode (made of a network of single-walled carbon nanotube film) and Si NWs, the electroluminescence performance and I ? V properties of flexible devices deteriorated compared to rigid devices. The developed PeLECs pave the way for further development of inorganic flexible uniformly light-emitting devices with improved properties.

Two-dimensional (2D) chiral halide perovskites (CHPs) have attracted broad interest due to their distinct spin-dependent properties and promising applications in chiroptics and spintronics. Here, we report a new type of 2D CHP single crystals, namely R/S-3BrMBA2PbBr4. The chirality of the as-prepared samples is confirmed by exploiting circular dichroism spectroscopy, indicating a successful chirality transfer from chiral organic cations to their inorganic perovskite sublattices. Furthermore, we observed bright photoluminescence spanning from 380 to 750 nm in R/S-3BrMBA2PbBr4 crystals at room temperature. Such broad photoluminescence originates from free excitons and self-trapped excitons. In addition, efficient second-harmonic generation (SHG) performance was observed in chiral perovskite single crystals with high circular polarization ratios and non-linear optical circular dichroism. This demonstrates that R/S-3BrMBA2PbBr4 crystals can be used to detect and generate left- and right-handed circularly polarized light. Our study provides a new platform to develop high-performance chiroptical and spintronic devices.

In recent years, as the dimensions of the conventional semiconductor technology is approaching the physical limits, while the multifunction circuits are restricted by the relatively fixed characteristics of the traditional metal?oxide?semiconductor field-effect transistors, reconfigurable devices that can realize reconfigurable characteristics and multiple functions at device level have been seen as a promising method to improve integration density and reduce power consumption. Owing to the ultrathin structure, effective control of the electronic characteristics and ability to modulate structural defects, two-dimensional (2D) materials have been widely used to fabricate reconfigurable devices. In this review, we summarize the working principles and related logic applications of reconfigurable devices based on 2D materials, including generating tunable anti-ambipolar responses and demonstrating nonvolatile operations. Furthermore, we discuss the analog signal processing applications of anti-ambipolar transistors and the artificial intelligence hardware implementations based on reconfigurable transistors and memristors, respectively, therefore highlighting the outstanding advantages of reconfigurable devices in footprint, energy consumption and performance. Finally, we discuss the challenges of the 2D materials-based reconfigurable devices.

Recently, self-powered ultraviolet photodetectors (UV PDs) based on SnO2 have gained increasing interest due to its feature of working continuously without the need for external power sources. Nevertheless, the production of the majority of these existing UV PDs necessitates additional manufacturing stages or intricate processes. In this work, we present a facile, cost-effective approach for the fabrication of a self-powered UV PD based on p-Si/n-SnO2 junction. The self-powered device was achieved simply by integrating a p-Si substrate with a n-type SnO2 microbelt, which was synthesized via the chemical vapor deposition (CVD) method. The high-quality feature, coupled with the belt-like shape of the SnO2 microbelt enables the favorable contact between the n-type SnO2 and p-type silicon. The built-in electric field created at the interface endows the self-powered performance of the device. The p-Si/n-SnO2 junction photodetector demonstrated a high responsivity (0.12 mA/W), high light/dark current ratio (>103), and rapid response speed at zero bias. This method offers a practical way to develop cost-effective and high-performance self-powered UV PDs.

Minority carrier lifetimes τ are a fundamental parameter in semiconductor devices, representing the average time it takes for excess minority carriers to recombine. This characteristic is crucial for understanding and optimizing the performance of semiconductor materials, as it directly influences charge carrier dynamics and overall device efficiency. This work presents a development of PbS thin film deposited by thermal evaporation, at which the PbS thin film was further employed for structural, optical properties, and τ. Especially, the PbS film is probed with an in-house setup for identifying the τ. The procedure is to subject the PbS thin film with a flashlight from a light source with a middle rotating frequency. The derived τ in the in-house characterization setup agrees well with the value from the higher cost characterizing approach of photoluminescence. Therefore, the in-house setup provides additional tools for identifying the τ values for semiconductor devices.

In DSP-based SerDes application, it is essential for AFE to implement a pre-ADC equalization to provide a better signal for ADC and DSP. To meet the various equalization requirements of different channel and transmitter configurations, this paper presents a 112 Gbps DSP-Based PAM4 SerDes receiver with a wide band equalization tuning AFE. The AFE is realized by implementing source degeneration transconductance, feedforward high-pass branch and inductive feedback peaking TIA. The AFE offers a flexible equalization gain tuning of up to 17.5 dB at Nyquist frequency without affecting the DC gain. With the proposed AFE, the receiver demonstrates eye opening after digital FIR equalization and achieves 6 × 10?9 BER with a 29.6 dB insertion loss channel.

In the applications such as food production, the environmental temperature should be measured continuously during the entire process, which requires an ultra-low-power temperature sensor for long-termly monitoring. Conventional temperature sensors trade the measurement accuracy with power consumption. In this work, we present a battery-free wireless temperature sensing chip for long-termly monitoring during food production. A calibrated oscillator-based CMOS temperature sensor is proposed instead of the ADC-based power-hungry circuits in conventional works. In addition, the sensor chip can harvest the power transferred by a remote reader to eliminate the use of battery. Meanwhile, the system conducts wireless bidirectional communication between the sensor chip and reader. In this way, the temperature sensor can realize both a high precision and battery-free operation. The temperature sensing chip is fabricated in 55 nm CMOS process, and the reader chip is implemented in 65 nm CMOS technology. Experimental results show that the temperature measurement error achieves ±1.6 °C from 25 to 50 °C, with battery-free readout by a remote reader.

A two-way K/Ka-band series-Doherty PA (SDPA) with a distributed impedance inverting network (IIN) for millimeter wave applications is presented in this article. The proposed distributed IIN contributes to achieve wideband linear and power back-off (PBO) efficiency enhancement. Implemented in 65 nm bulk CMOS technology, this work realizes a measured 3 dB bandwidth of 15.5 GHz with 21.2 dB peak small-signal gain at 34.2 GHz. Under 1-V power supply, it achieves OP1dB over 13.4 dBm and Psat over 16 dBm between 21 to 30 GHz. The measured maximum Psat, OP1dB, peak/OP1dB/6dBPBO PAE results are 17.5, 14.7 dBm, and 28.2%/23.2%/13.2%. Without digital pre-distortion (DPD) and equalization, EVMs are lower than ?25.2 dB for 200 MHz 64-QAM signals. Besides, this work achieves ?33.35, ?23.52, and ?20 dB EVMs for 100 MHz 256-QAM, 600 MHz 64-QAM and 2 GHz 16-QAM signals at 27 GHz without DPD and equalization.

This paper introduces a high-precision bandgap reference (BGR) designed for battery management systems (BMS), featuring an ultra-low temperature coefficient (TC) and line sensitivity (LS). The BGR employs a current-mode scheme with chopped op-amps and internal clock generators to eliminate op-amp offset. A low dropout regulator (LDO) and a pre-regulator enhance output driving and LS, respectively. Curvature compensation enhances the TC by addressing higher-order nonlinearity. These approaches, effective near room temperature, employs trimming at both 20 and 60 °C. When combined with fixed curvature correction currents, it achieves an ultra-low TC for each chip. Implemented in a CMOS 180 nm process, the BGR occupies 0.548 mm2 and operates at 2.5 V with 84 μA current draw from a 5 V supply. An average TC of 2.69 ppm/°C with two-point trimming and 0.81 ppm/°C with multi-point trimming are achieved over the temperature range of ?40 to 125 °C. It accommodates a load current of 1 mA and an LS of 42 ppm/V, making it suitable for precise BMS applications.

The (010)-oriented substrates of β-Ga2O3 are endowed with the maximum thermal conductivity and fastest homoepitaxial rate, which is the preferred substrate direction for high-power devices. However, the size of (010) plane wafer is critically limited by die in the commercial edge-defined film-fed growth (EFG) method. It is difficult to grow the β-Ga2O3 crystal with (010) principal face due to the (100) and (001) are cleavage planes. Here, the 2-inch diameter (010) principal-face β-Ga2O3 single crystal is successfully designed and grown by improved EFG method. Unlike previous reported techniques, the single crystals are pulled with [001] direction, and in this way the (010) wafers can be obtained from the principal face. In our experiments, tree-like defects (TLDs) in (010) principal-face bulk crystals are easy to generate. The relationship between stability of growth interface and origin of TLDs are thoroughly discussed. The TLDs are successfully eliminated by optimizing growth conditions. The high crystalline quality of (010)-oriented substrates are comprehensive demonstrated by full width at half maximum (FWHM) with 50.4 arcsec, consistent orientation arrangement of (010) plane, respectively. This work shows that the (010)-oriented substrates can be obtained by EFG method, predicting the commercial prospects of large-scale (010)-oriented β-Ga2O3 substrates.

As traditional von Neumann architectures face limitations in handling the demands of big data and complex computational tasks, neuromorphic computing has emerged as a promising alternative, inspired by the human brain's neural networks. Volatile memristors, particularly Mott and diffusive memristors, have garnered significant attention for their ability to emulate neuronal dynamics, such as spiking and firing patterns, enabling the development of reconfigurable and adaptive computing systems. Recent advancements include the implementation of leaky integrate-and-fire neurons, Hodgkin?Huxley neurons, optoelectronic neurons, and time-surface neurons, all utilizing volatile memristors to achieve efficient, low-power, and highly integrated neuromorphic systems. This paper reviews the latest progress in volatile memristor-based artificial neurons, highlighting their potential for energy-efficient computing and integration with artificial synapses. We conclude by addressing challenges such as improving memristor reliability and exploring new architectures to advance memristor-based neuromorphic computing.

In order to solve the problems of low overload power in MEMS cantilever beams and low sensitivity in traditional MEMS fixed beams, a novel MEMS microwave power detection chip based on the dual-guided fixed beam is designed. A gap between guiding beams and measuring electrodes is designed to accelerate the release of the sacrificial layer, effectively enhancing chip performance. A load sensing model for the MEMS fixed beam microwave power detection chip is proposed, and the mechanical characteristics are analyzed based on the uniform load applied. The overload power and sensitivity are investigated using the load sensing model, and experimental results are compared with theoretical results. The detection chip exhibits excellent microwave characteristic in the 9?11 GHz frequency band, with a return loss less than ?10 dB. At a signal frequency of 10 GHz, the theoretical sensitivity is 13.8 fF/W, closely matching the measured value of 14.3 fF/W, with a relative error of only 3.5%. These results demonstrate that the proposed load sensing model provides significant theoretical support for the design and performance optimization of MEMS microwave power detection chips.

Computing-in-memory (CIM) has been a promising candidate for artificial-intelligent applications thanks to the absence of data transfer between computation and storage blocks. Resistive random access memory (RRAM) based CIM has the advantage of high computing density, non-volatility as well as high energy efficiency. However, previous CIM research has predominantly focused on realizing high energy efficiency and high area efficiency for inference, while little attention has been devoted to addressing the challenges of on-chip programming speed, power consumption, and accuracy. In this paper, a fabricated 28 nm 576K RRAM-based CIM macro featuring optimized on-chip programming schemes is proposed to address the issues mentioned above. Different strategies of mapping weights to RRAM arrays are compared, and a novel direct-current ADC design is designed for both programming and inference stages. Utilizing the optimized hybrid programming scheme, 4.67× programming speed, 0.15× power saving and 4.31× compact weight distribution are realized. Besides, this macro achieves a normalized area efficiency of 2.82 TOPS/mm2 and a normalized energy efficiency of 35.6 TOPS/W.

The novel HfO2-based ferroelectric field effect transistor (FeFET) is considered a promising candidate for next-generation nonvolatile memory (NVM). However, a series of reliability issues caused by the fatigue effect hinder its further development. Therefore, a comprehensive understanding of the fatigue mechanisms of the device and optimization strategies is essential for its application. The fundamental mechanism of the fatigue effect is attributed to charge trapping and trap generation based on the current studies, and the underlying causes, occurrence locations and specific impacts are analyzed in this review. In particular, the asymmetric trapping/detrapping of electrons and holes, as well as the relationship between the ferroelectric (FE) polarization and charge trapping, are given particular attention. After categorizing and summarizing the current progress, we propose a series of optimization strategies derived based on the fatigue mechanisms.

In the implementation of quantum key distribution, Security certification is a prerequisite for social deployment. Transmitters in decoy-BB84 systems typically employ gain-switched semiconductor lasers (GSSLs) to generate optical pulses for encoding quantum information. However, the working state of the laser may violate the assumption of pulse independence. Here, we explored the dependence of intensity fluctuation and high-order correlation distribution of optical pulses on driving currents at 2.5 GHz. We found the intensity correlation distribution had a significant dependence on the driving currents, which would affect the final key rate. By utilizing rate equations in our simulation, we confirmed the fluctuation and correlation originated from the instability of gain-switched laser driven at a GHz-repetitive frequency. Finally, we evaluated the impact of intensity fluctuation on the secure key rate. This work will provide valuable insights for assessing whether the transmitter is operating at optimal state in practice.

Complementary inverter is the basic unit for logic circuits, but the inverters based on full oxide thin-film transistors (TFTs) are still very limited. The next challenge is to realize complementary inverters using homogeneous oxide semiconductors. Herein, we propose the design of complementary inverter based on full ZnO TFTs. Li?N dual-doped ZnO (ZnO:(Li,N)) acts as the p-type channel and Al-doped ZnO (ZnO:Al) serves as the n-type channel for fabrication of TFTs, and then the complementary inverter is produced with p- and n-type ZnO TFTs. The homogeneous ZnO-based complementary inverter has typical voltage transfer characteristics with the voltage gain of 13.34 at the supply voltage of 40 V. This work may open the door for the development of oxide complementary inverters for logic circuits.

As a type of charge-balanced power device, the performance of super-junction MOSFETs (SJ-MOS) is significantly influenced by fluctuations in the fabrication process. To overcome the relatively narrow process window of conventional SJ-MOS, an optimized structure "vertical variable doping super-junction MOSFET (VVD-SJ)" is proposed. Based on the analysis using the charge superposition principle, it is observed that the VVD-SJ, in which the impurity concentration of the P-pillar gradually decreases while that of the N-pillar increases from top to bottom, improves the electric field distribution and mitigates charge imbalance (CIB). Experimental results demonstrate that the optimized 600 V VVD-SJ achieves a 35.90% expansion of the process window.

Interfacial defects and environmental instability at perovskite surfaces pose significant challenges for inverted perovskite solar cells (PSCs). Surface post-treatment strategies have emerged as a viable approach to improve film quality and passivate defects. Although organic molecules can passivate both surfaces and grain boundaries via hydrogen or covalent bonding, their limited adsorption specificity often results in incomplete defect neutralization. In this work, we introduce a bilayer passivation approach employing phenethylammonium iodide (PEAI) and n-octylammonium iodide (OAI) to concurrently mitigate non-radiative recombination and improve stability. PEAI passivates undercoordinated Pb2+ at grain boundaries and surfaces, effectively eliminating deep-level traps and suppressing non-radiative losses. Meanwhile, OAI forms a hydrophobic barrier on the perovskite surface through its long alkyl chains, inhibiting moisture penetration without compromising interfacial charge transport. As a result, the perovskite film exhibits significantly enhanced optoelectronic performance and environmental stability, achieving a champion power conversion efficiency (PCE) of 24.48%.

Although perovskite solar cells (PSCs) demonstrate outstanding power conversion efficiency (PCE), their practical applications are still limited by stability issues caused by various problems such as poor crystal quality triggered structural instability. Herein, to address the structural instability of perovskites, we introduced a polymer additive, poly-L-lysine hydrobromide (PLL), into the perovskite precursor to promote perovskite crystal growth, thereby constructing a stable crystal structure. The results show that the introduction of PLL modulates the colloidal aggregation state in the precursor solution, provides longer time for growth of perovskite and successfully realizes the formation of large-sized perovskite films with high crystallinity. More importantly, owing to its hydrophobic long-chain structure and the widespread distribution of C=O and NH on the chain, PLL firmly locks the perovskite crystals, enhancing their structural stability while blocking the intrusion of external factors such as water molecules, significantly enhances the overall stability of the device. The results show that the PLL-based PSC has negligible hysteresis and its PCE is improved from 22.20% to 23.66%. while the PLL-modified perovskite films and devices demonstrate excellent thermal and environmental stability. These findings highlight PLL as a promising additive for optimizing perovskite crystallization, offering guidance for fabricating efficient and stable photovoltaic devices.

Owing to their low toxicity and remarkable stability, perovskites based on antimony and bismuth have garnered significant interest in recent years. However, A3B2X9 perovskite materials derived from antimony and bismuth face several challenges, including excessively wide band gaps, elevated defect densities, and suboptimal film quality, all of which hinder advancements in device efficiency. While extensive studies have been undertaken to investigate the effects of modulating the A-site and X-site elements in lead-free A3B2X9 perovskites, there remains a notable scarcity of reports addressing the impact of modifications to the B-site element. In this study, we investigated the alloying of antimony and bismuth within the 2D Cs3B2I6Br3 perovskite. By systematically varying the ratios of two elements, we found that the incorporation of both antimony and bismuth at the B-site significantly enhances the quality of the perovskite films. Our findings indicate that a 1 : 1 ratio of antimony to bismuth produces the densest films, the highest photoluminescence intensity, and superior photovoltaic performance. Ultimately, the devices fabricated using this optimal ratio achieved an open-circuit voltage (VOC) of 1.01 V and a power conversion efficiency (PCE) of 0.645%.

All-perovskite tandem solar cells (ATSCs) have the potential to surpass the Shockley?Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead (Sn–Pb) perovskite solar cells (PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn2+ oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate (EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn2+ and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin?lead PSCs reached a power conversion efficiency (PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn?Pb PSCs.

High-performance perovskite photodetectors with self-driven characteristic usually need electron/hole transport layers to extract carriers. However, these devices with transport layer structure are prone to result in a poor perovskite/transport layer interface, which restricts the performance and stability of the device. To solve this problem, this work reports a novel device structure in which perovskite nanowires are in-situ prepared on PbI2, which serves as both a reaction raw material and efficient carrier extraction layer. By optimizing the thickness of PbI2, nanowire growth time, and ion exchange time, a self-driven photodetector with an ITO/PbI2/CsPbBr3/carbon structure is constructed. The optimized device achieves excellent performance with the responsivity of 0.33 A/W, the detectivity of as high as 3.52 × 1013 Jones. Furthermore, the device can detect the light with its optical power lowered to 0.1 nW/cm2. This research provides a new method for preparing perovskite nano/micro devices with simple structure but excellent performance.

Integrated perovskite-organic solar cells (IPOSCs) offer a promising hybrid approach that combines the advantages of perovskite and organic solar cells, enabling efficient photon absorption across a broad spectrum with a simplified architecture. However, challenges such as limited charge mobility in organic bulk heterojunction (BHJ) layers, and energy-level mismatch at the perovskite/BHJ interface still sustain. Recent advancements in non-fullerene acceptors (NFAs), interfacial engineering, and emerging materials have improved charge transfer/transport, and overall power conversion efficiency (PCE) of IPOSCs. This review explores key developments in IPOSCs, focusing on low-bandgap materials for near-infrared absorption, energy alignment optimization, and strategies to enhance photocurrent density and device performance. Future innovations in material selection and device architecture will be crucial for further improving the efficiency of IPOSCs, bringing them closer to practical application in next-generation photovoltaic technologies.

Perovskite solar cells (PSCs) have become a hot topic in the field of renewable energy due to their excellent power conversion efficiency and potential for low-cost manufacturing. The hole transport layer (HTL), as a key component of PSCs, plays a crucial role in the cell's overall performance. Magnetron sputtering NiOx has attracted widespread attention due to its high carrier mobility, excellent stability, and suitability for large-scale production. Herein, an insightful summary of the recent progress of magnetron sputtering NiOx as the HTL of PSCs is presented to promote its further development. This review summarized the basic properties of magnetron sputtering NiOx thin film, the key parameters affecting the optoelectronic properties of NiOx thin films during the magnetron-sputtering process, and the performance of the corresponding PSCs. Special attention was paid to the interfacial issues between NiOx and perovskites, and the modification strategies were systematically summarized. Finally, the challenges of sputtering NiOx technology and the possible development opportunities were concluded and discussed.

Halide perovskites have attracted great interest as active layers in optoelectronic devices. Among perovskites with diverse compositions, α-FAPbI3 is of utmost importance with great optoelectronic properties and a decent bandgap of 1.48 eV. However, the α-phase suffers an irreversible transition to the photo-inactive δ-phase, whereas the δ-phase is usually regarded as useless phase with poor optoelectronic properties. Therefore, it is commonly accepted that the thermodynamic stable δ-FAPbI3 greatly limits the application of FAPbI3. Every coin has two sides, although the δ-phase is difficult to apply as photoelectrical active layers, it is possible to combine δ-FAPbI3 with α-FAPbI3 to realize functional applications. Firstly, this review analyzes the cause of the contrasting properties between α- and δ-FAPbI3, where the stronger electron?phonon coupling in 1D hexagonal δ-FAPbI3 restricts its internal carrier and phonon transport. Secondly, the factors affecting the phase transitions and strategies to control phase transition between α- and δ-FAPbI3 are presented. Finally, some functional applications of δ-FAPbI3 in combination with α-FAPbI3 are given according to previous reports. By and large, we hope to introduce δ-FAPbI3 from another perspective and give some insights into its unique properties, hopefully providing new strategies for the subsequent advances to FAPbI3.

Due to advantages of high power-conversion efficiency (PCE), large power-to-weight ratio (PWR), low cost and solution processibility, flexible perovskite solar cells (f-PSCs) have attracted extensive attention in recent years. The PCE of f-PSCs has developed rapidly to over 25%, showing great application prospects in aerospace and wearable electronic devices. This review systematically sorts device structures and compositions of f-PSCs, summarizes various methods to improve its efficiency and stability recent years. In addition, the applications and potentials of f-PSCs in space vehicle and aircraft was discussed. At last, we prospect the key scientific and technological issues that need to be addressed for f-PSCs at current stage.

Traditional p-type colloidal quantum dot (CQD) hole transport layers (HTLs) used in CQD solar cells (CQDSCs) are commonly based on organic ligands exchange and the layer-by-layer (LbL) technique. Nonetheless, the ligand detachment and complex fabrication process introduce surface defects, compromising device stability and efficiency. In this work, we propose a solution-phase ligand exchange (SPLE) method utilizing inorganic ligands to develop stable p-type lead sulfide (PbS) CQD inks for the first time. Various amounts of tin (II) iodide (SnI2) were mixed with lead halide (PbX2; X = I, Br) in the ligand solution. By precisely controlling the SnI? concentration, we regulate the transition of PbS QDs from n-type to p-type. PbS CQDSCs were fabricated using two different HTL approaches: one with 1,2-ethanedithiol (EDT)-passivated QDs via the LbL method (control) and another with inorganic ligand-passivated QD ink (target). The target devices achieved a higher power conversion efficiency (PCE) of 10.93%, compared to 9.83% for the control devices. This improvement is attributed to reduced interfacial defects and enhanced carrier mobility. The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands, paving the way for high-performance and flexible CQD-based optoelectronic devices.

The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots (QDs), making them versatile building blocks for next-generation light-emitting diodes (LEDs). This study investigates how quantum confinement governs the charge transport, exciton dynamics, and emission efficiency in QD-LEDs, using CsPbI3 QDs as a model system. By systematically varying QD sizes, we reveal size-dependent trade-offs in LED performance, such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities. Our findings offer critical insights into the design of high-performance QD-LEDs, paving the way for scalable and energy-efficient optoelectronic devices.

High-performance flexible pressure sensors have garnered significant attention in fields such as wearable electronics and human-machine interfaces. However, the development of flexible pressure sensors that simultaneously achieve high sensitivity, a wide detection range, and good mechanical stability remains a challenge. In this paper, we propose a flexible piezoresistive pressure sensor based on a Ti3C?Tx (MXene)/polyethylene oxide (PEO) composite nanofiber membrane (CNM). The sensor, utilizing MXene (0.4 wt%)/PEO (5 wt%), exhibits high sensitivity (44.34 kPa?1 at 0?50 kPa, 12.99 kPa?1 at 50?500 kPa) and can reliably monitor physiological signals and other subtle cues. Moreover, the sensor features a wide detection range (0?500 kPa), fast response and recovery time (~150/45 ms), and excellent mechanical stability (over 10 000 pressure cycles at maximum load). Through an MXene/PEO sensor array, we demonstrate its applications in human physiological signal monitoring, providing a reliable way to expand the application of MXene-based flexible pressure sensors.

In the rapidly evolving field of modern technology, near-infrared (NIR) photodetectors are extremely crucial for efficient and reliable optical communications. The graphene/GaAs Schottky junction photodetector leverages graphene’s exceptional carrier mobility and broadband absorption, coupled with GaAs’s strong absorption in the NIR spectrum, to achieve high responsivity and rapid response times. Here, we present a NIR photodetector employing a graphene/GaAs Schottky junction tailored for communication wavelengths. We fabricated high-performance graphene/GaAs Schottky junction devices with interdigitated electrodes of varying finger widths, systematically investigating their impact on device performance. The experimental results demonstrate that incorporating interdigitated electrodes significantly enhances the collection efficiency of photogenerated carriers in graphene/GaAs photodetectors. When illuminated by 808 nm NIR light at an intensity of 7.23 mW/cm2, the device achieves an impressive switch ratio of 10?, along with a high responsivity of 40.1 mA/W and a remarkable detectivity of 2.89 × 1013 Jones. Additionally, the device is characterized by rapid response times, with rise and fall times of 18.5 and 17.5 μs, respectively, at a 3 dB bandwidth. These findings underscore the significant potential of high-performance graphene/GaAs photodetectors for applications in NIR optoelectronic systems.

Perovskite materials have emerged as promising candidates for various optoelectronic applications owing to their remarkable optoelectronic properties and easy solution processing. Metal halide perovskites, as direct-bandgap semiconductors, show an excellent class of optical gain media, which makes them applicable to the development of low-threshold or even thresholdless lasers. This mini review explores recent advances in perovskite-based laser technology, which have led to chiral single-mode microlasers, low-threshold, external-cavity-free lasing devices at room temperature, and other innovative device architectures. Including self-assembled CsPbBr3 microwires that enable edge lasing. Realized continuous-wave (CW) pumped lasing by perovskite material pushes the research of electrically driven perovskite lasers. The capacity to regulate charge transport in halide perovskites further enhances their applicability in optoelectronic systems. The ongoing integration of perovskite materials with advanced photonic structures holds excellent potential for future innovations in laser technology and photovoltaics. We also highlight the transformative potential of perovskite materials in advancing the next generation of efficient and integrated optoelectronic devices.

Colloidal quantum dots (CQDs) are highly regarded for their outstanding photovoltaic characteristics, including excellent color purity, stability, high photoluminescence quantum yield (PLQY), narrow emission spectra, and ease of solution processing. Despite significant progress in quantum dot light-emitting diodes (QLEDs) technology since its inception in 1994, blue QLEDs still fall short in efficiency and lifespan compared to red and green versions. The toxicity concerns associated with Cd/Pb-based quantum dots (QDs) have spurred the development of heavy-metal-free alternatives, such as group Ⅱ?Ⅵ (e.g., ZnSe-based QDs), group Ⅲ?Ⅴ (e.g., InP, GaN QDs), and carbon dots (CDs). In this review, we discuss the key properties and development history of quantum dots (QDs), various synthesis approaches, the role of surface ligands, and important considerations in developing core/shell (C/S) structured QDs. Additionally, we provide an outlook on the challenges and future directions for blue QLEDs.

Semiconductor colloidal quantum wells (CQWs) with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties. In this study, we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7, synthesized via thermal injection and atomic layer (c-ALD) deposition techniques. Through a combination of spectroscopic ellipsometry (SE) and first-principles calculations, we demonstrate the significant tunability of the bandgap, refractive index, and extinction coefficient, driven by quantum confinement effects. Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases. Furthermore, by employing a detailed analysis of the absorption spectra, accounting for exciton localization and asymmetric broadening, we precisely capture the relationship between monolayer number and exciton binding energy. These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.

In order to address challenges posed by the reduction in transistor size, researchers are concentrating on two-dimensional (2D) materials with high dielectric constants and large band gaps. Monoclinic ZrO2 (m-ZrO2) has emerged as a promising gate dielectric material due to its suitable dielectric constant, wide band gap, ideal valence-band offset, and good thermodynamic stability. However, current deposition methods face compatibility issues with 2D semiconductors, highlighting the need for high-quality dielectrics and interfaces. Here, high-quality 2D m-ZrO2 single crystals are successfully prepared using a one-step chemical vapor deposition (CVD) method, aided by 5A molecular sieves for oxygen supply. The prepared ZrO2 is utilized as a gate dielectric in the construction of MoS2 field-effect transistors (FETs) to investigate its electrical property. The FETs exhibit a high carrier mobility of up to 5.50 cm2·V?1·s?1, and a current switching ratio (Ion/off) of approximately 104, which aligns with the current standards of logic circuits, indicating that ZrO2 has application value as a gate dielectric. The successful one-step preparation of single-crystal ZrO2 paves the way for the utilization of high-κ gate dielectrics and creates favorable conditions for the development of high-performance semiconductor devices, offering new possibilities for transistor miniaturization.

In this work, we studied the persistent photoconductivity (PPC) spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity. The studies were performed in a wide radiation quantum energy range of 0.62–3.1 eV both at T = 4.2 K and at T = 77 K. Common features of the PPC spectra for all structures were revealed, and their relation to the presence of a CdTe cap layer in all structures and the appropriate cadmium fraction in the CdHgTe barrier layers was shown. One of the features was associated with the presence of a deep level in the CdTe layer. In addition, the oscillatory behavior of the PPC spectra in the region from 0.8–1.1 eV to 1.2–1.5 eV was observed. It is associated with the cascade emission of longitudinal optical phonons in CdHgTe barrier.

Lead chalcohalides (PbYX, X = Cl, Br, I; Y = S, Se) is an extension of the classic Pb chalcogenides (PbY). Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly improved optoelectronic performance. In this work, we studied the effect of introducing halogen precursors on the structure of classical PbS nanocrystals (NCs) during the synthesis process and realized the preparation of PbS/Pb3S2X2 core/shell structure for the first time. The core/shell structure can effectively improve their optical properties. Furthermore, our approach enables the synthesis of Pb3S2Br2 that had not yet been reported. Our results not only provide valuable insights into the heterogeneous integration of PbYX and PbY materials to elevate material properties but also provide an effective method for further expanding the preparation of PbYX material systems.

In the present work, the high uniform 6-inch single-crystalline AlN template is successfully achieved by high temperature annealing technique, which opens up the path towards industrial application in power device. Moreover, the outstanding crystalline-quality is confirmed by Rutherford backscattering spectrometry (RBS). In accompanied with the results from X-ray diffraction, the RBS results along both [0001] and [12ˉ13] reveal that the in-plane lattice is effectively reordered by high temperature annealing. In addition, the constant Φepi angle between [0001] and [12ˉ13] at different depths of 31.54° confirms the uniform compressive strain inside the AlN region. Benefitting from the excellent crystalline quality of AlN template, we can epitaxially grow the enhanced-mode high electron mobility transistor (HEMT) with a graded AlGaN buffer as thin as only ~300 nm. Such an ultra-thin AlGaN buffer layer results in the wafer-bow as low as 18.1 μm in 6-inch wafer scale. The fabricated HEMT devices with 16 μm-LGD exhibits a threshold voltage (VTH) of 1.1 V and a high OFF-state breakdown voltage (VBD) over 1400 V. Furthermore, after 200 V high-voltage OFF-state stress, the current collapse is only 13.6%. Therefore, the advantages of both 6-inch size and excellent crystallinity announces the superiority of single-crystalline AlN template in low-cost electrical power applications.

Quantum dot (QD)-based infrared photodetector is a promising technology that can implement current monitoring, imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction. The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 1012 Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector (4.66 × 1011 Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.

This paper presents a compact ultra-low-power phase-locked loop (PLL) based binary phase-shift keying (BPSK) demodulator. The loop-filter-less (LPF-less) PLL is proposed to make phase of PLL output carrier signal track the phase of BPSK signal in real time. Thus, the maximum date rate can be significantly extended to the half of the carrier frequency (fcarrier) with a very compact size compared to prior PLL-based BPSK demodulators. Furthermore, eliminating all the static power in our LPF-less PLL, the energy efficiency is obviously improved. Fabricated in a 40-nm CMOS process, our prototype occupies 0.0012-mm2 core active area, and achieves the maximum data rate of 6.78 Mb/s (fcarrier/2) at fcarrier of 13.56 MHz. The power consumption and energy efficiency is 4.47 μW and 0.66 pJ/bit at 6.78-Mb/s data rate, respectively.

Magnetic tunnel junction (MTJ) based spin transfer torque magnetic random access memory (STT-MRAM) has been gaining tremendous momentum in high performance microcontroller (MCU) applications. As eFlash-replacement type MRAM approaches mass production, there is an increasing demand for non-volatile RAM (nvRAM) technologies that offer fast write speed and high endurance. In this work, we demonstrate highly reliable 4 Mb nvRAM type MRAM suitable for industry and auto grade-1 applications. This nvRAM features retention over 10 years at 125 °C, endurance of 1 × 1012 cycles with 20 ns write speed, making it ideal for applications requiring both high speed and broad temperature ranges. By employing innovative MTJ materials, process engineering, and a co-optimization of process and design, reliable read and write performance across the full temperature range between ?40 to 125 °C, and array yield that meets sub-1 ppm error rate was significantly improved from 0 to above 95%, a concrete step toward applications.

In this study, we investigate an innovative hybrid structure of silicon nanowires (SiNWs) coated with polyaniline (PANI):metal oxide (MOx) nanoparticles, i.e., WO3 and TiO2, for respiratory sensing. To date, few attempts have been made to utilize such hybrid structures for that application. The SiNWs were fabricated using metal-assisted chemical etching (MACE), whereas PANI:MOxwas deposited using chemical oxidative polymerization. The structures were characterized using Raman spectroscopy, X-ray diffraction, and scanning electron microscopy. The sensing characteristics revealed that the hybrid sensor exhibited a considerably better response than pure SiNWs:MOxand SiNWs:PANI. Such an enhancement in sensitivity is attributed to the formation of a p?n heterojunction between PANI and MOx, the wider conduction channel provided by PANI, increased porosity in SiNWs/PANI:WO3 hybrid structures, which creates active sites, increased oxygen vacancies, and the large surface area compared to that available in pure MOxnanoparticles. Furthermore, less baseline drift and increased sensor stability were established for the SiNWs structure coated with PANI:WO3, as compared to PANI:TiO2.

Quantum well infrared photodetectors (QWIPs) based on intersubband transitions hold significant potential for high bandwidth operation. In this work, we establish a carrier transport optimization model incorporating electron injection at the emitter to investigate the carrier dynamics time and impedance spectroscopy in GaAs/AlGaAs QWIPs. Our findings provide novel evidence that the escape time of electrons is the key limiting factor for the 3-dB bandwidth of QWIPs. Moreover, to characterize the impact of carrier dynamics time and non-equilibrium space charge region on impedance, we developed an equivalent circuit model where depletion region resistance and capacitance are employed to describe non-equilibrium space charge region. Using this model, we discovered that under illumination, both net charge accumulation caused by variations in carrier dynamics times within quantum wells and changes in width of non-equilibrium space charge region exert different dominant influences on depletion region capacitance at various doping concentrations.

Synchrotron method of resonant X-ray reflectivity 2D mapping has been applied to study ultrathin epitaxial layers of WS2 grown by pulsed laser deposition on Al2O3(0001) substrates. The measurements were carried out across the L absorption edge of tungsten to perform depth-dependent element-selective analysis sensitive to potential chemical modification of the WS2 layer in ambient conditions. Despite the few monolayer thickness of the studied film, the experimentally measured maps of reflectance as a function of incident angle and photon energy turned out to be quite informative showing well-pronounced interference effects near W absorption edge at 10 210 eV. The synchrotron studies were complemented with conventional non-resonant reflectance measurements carried out in the laboratory at a fixed photon energy corresponding to Cu Kα emission. The reconstruction of the depth and energy dependent scattering length density within the studied multilayers was carried out using the OpenCL empowered fitting software utilizing spectral shaping algorithm which does not rely on the pre-measured reference absorption spectra. A thin WOx layer has been revealed at the surface of the WS2 layer pointing out to the effect of water assisted photo-oxidation reported in a number of works related to ultrathin layers of transition metal dichalcogenides.

Full-Stokes polarimeters can detect the polarization states of light, which is critical for the next-generation optical and optoelectronic systems. Traditional full-Stokes polarimeters are either based on bulky optical systems or complex metasurface structures, which cause the system complexity with unessential energy loss. Recently, filterless on-chip full-Stokes polarimeters have been demonstrated by using optical anisotropic materials which are able to detect the circularly polarized light. Nevertheless, those on-chip full-Stokes polarimeters have either the limited detection wavelength range or relatively poor device performance that need to be further improved. Here, we report the high performance broadband full-Stokes polarimeters based on rhenium disulfide (ReS2). While the anisotropic structure of the ReS2 introduces the in-plane optical anisotropy for linearly polarized light (LP) detection, Schottky contacts formed by the ReS2?Au could break the symmetry, which can detect circularly polarized (CP) light. By building a proper model, all four Stokes parameters can be extracted by using the ReS2 nanobelt device. The device delivers a photoresponsivity of 181 A/W, a detectivity of 6.8 × 1010 Jones and can sense the four Stokes parameters of incident light within a wide range of wavelength from 565?800 nm with reasonable average errors. We believe our study provides an alternative strategy to develop high performance broadband on-chip full-Stokes polarimeters.

Multiple quantum well (MQW) Ⅲ-nitride diodes that can simultaneously emit and detect light feature an overlapping region between their electroluminescence and responsivity spectra, which allows them to be simultaneously used as both a transmitter and a receiver in a wireless light communication system. Here, we demonstrate a mobile light communication system using a time-division multiplexing (TDM) scheme to achieve bidirectional data transmission via the same optical channel. Two identical blue MQW diodes are defined by software as a transmitter or a receiver. To address the light alignment issue, an image identification module integrated with a gimbal stabilizer is used to automatically detect the locations of moving targets; thus, underwater audio communication is realized via a mobile blue-light TDM communication mode. This approach not only uses a single link but also integrates mobile nodes in a practical network.

Optical network-on-chip (ONoC) systems have emerged as a promising solution to overcome limitations of traditional electronic interconnects. Efficient ONoC architectures rely on optical routers, enabling high-speed data transfer, efficient routing, and scalability. This paper presents a comprehensive survey analyzing optical router designs, specifically microring resonators (MRRs), Mach?Zehnder interferometers (MZIs), and hybrid architectures. Selected comparison criteria, chosen for their critical importance, significantly impact router functionality and performance. By emphasizing these criteria, valuable insights into the strengths and limitations of different designs are gained, facilitating informed decisions and advancements in optical networking. While other factors contribute to performance and efficiency, the chosen criteria consistently address fundamental elements, enabling meaningful evaluation. This work serves as a valuable resource for beginners, providing a solid foundation in understanding ONoC and optical routers. It also offers an in-depth survey for experts, laying the groundwork for further exploration. Additionally, the importance of considering design constraints and requirements when selecting an optimal router design is highlighted. Continued research and innovation will enable the development of efficient optical router solutions that meet the evolving needs of modern computing systems. This survey underscores the significance of ongoing advancements in the field and their potential impact on future technologies.

The rapid growth of artificial intelligence has accelerated data generation, which increasingly exposes the limitations faced by traditional computational architectures, particularly in terms of energy consumption and data latency. In contrast, data-centric computing that integrates processing and storage has the potential of reducing latency and energy usage. Organic optoelectronic synaptic transistors have emerged as one type of promising devices to implement the data-centric computing paradigm owing to their superiority of flexibility, low cost, and large-area fabrication. However, sophisticated functions including vector-matrix multiplication that a single device can achieve are limited. Thus, the fabrication and utilization of organic optoelectronic synaptic transistor arrays (OOSTAs) are imperative. Here, we summarize the recent advances in OOSTAs. Various strategies for manufacturing OOSTAs are introduced, including coating and casting, physical vapor deposition, printing, and photolithography. Furthermore, innovative applications of the OOSTA system integration are discussed, including neuromorphic visual systems and neuromorphic computing systems. At last, challenges and future perspectives of utilizing OOSTAs in real-world applications are discussed.

High-quality AlN epitaxial layers with low dislocation densities and uniform crystal quality are essential for next-generation optoelectronic and power devices. This study reports the epitaxial growth of 6-inch AlN films on 17 nm AlN/sapphire templates using metal?organic chemical vapor deposition (MOCVD). Comprehensive characterization reveals significant advancements in crystal quality and uniformity. Atomic force microscopy (AFM) shows progressive surface roughness reduction during early growth stages, achieving stabilization at a root mean square (RMS) roughness of 0.216 nm within 3 min, confirming successful 2D growth mode. X-ray rocking curve (XRC) analysis indicates a marked reduction in the (0002) reflection full width at half maximum (FWHM), from 445 to 96 arcsec, evidencing effective dislocation annihilation. Transmission electron microscopy (TEM) demonstrates the elimination of edge dislocations near the AlN template interface. Stress analysis highlights the role of a highly compressive 17 nm AlN template (5.11 GPa) in facilitating threading dislocation bending and annihilation, yielding a final dislocation density of ~1.5 × 107 cm?2. Raman spectroscopy and XRC mapping confirm excellent uniformity of stress and crystal quality across the wafer. These findings demonstrate the feasibility of this method for producing high-quality, large-area, atomically flat AlN films, advancing applications in optoelectronics and power electronics.

Recently, for developing neuromorphic visual systems, adaptive optoelectronic devices become one of the main research directions and attract extensive focus to achieve optoelectronic transistors with high performances and flexible functionalities. In this review, based on a description of the biological adaptive functions that are favorable for dynamically perceiving, filtering, and processing information in the varying environment, we summarize the representative strategies for achieving these adaptabilities in optoelectronic transistors, including the adaptation for detecting information, adaptive synaptic weight change, and history-dependent plasticity. Moreover, the key points of the corresponding strategies are comprehensively discussed. And the applications of these adaptive optoelectronic transistors, including the adaptive color detection, signal filtering, extending the response range of light intensity, and improve learning efficiency, are also illustrated separately. Lastly, the challenges faced in developing adaptive optoelectronic transistor for artificial vision system are discussed. The description of biological adaptive functions and the corresponding inspired neuromorphic devices are expected to provide insights for the design and application of next-generation artificial visual systems.

The traditional von Neumann architecture faces inherent limitations due to the separation of memory and computation, leading to high energy consumption, significant latency, and reduced operational efficiency. Neuromorphic computing, inspired by the architecture of the human brain, offers a promising alternative by integrating memory and computational functions, enabling parallel, high-speed, and energy-efficient information processing. Among various neuromorphic technologies, ion-modulated optoelectronic devices have garnered attention due to their excellent ionic tunability and the availability of multidimensional control strategies. This review provides a comprehensive overview of recent progress in ion-modulation optoelectronic neuromorphic devices. It elucidates the key mechanisms underlying ionic modulation of light fields, including ion migration dynamics and capture and release of charge through ions. Furthermore, the synthesis of active materials and the properties of these devices are analyzed in detail. The review also highlights the application of ion-modulation optoelectronic devices in artificial vision systems, neuromorphic computing, and other bionic fields. Finally, the existing challenges and future directions for the development of optoelectronic neuromorphic devices are discussed, providing critical insights for advancing this promising field.

To address the increasing demand for massive data storage and processing, brain-inspired neuromorphic computing systems based on artificial synaptic devices have been actively developed in recent years. Among the various materials investigated for the fabrication of synaptic devices, silicon carbide (SiC) has emerged as a preferred choices due to its high electron mobility, superior thermal conductivity, and excellent thermal stability, which exhibits promising potential for neuromorphic applications in harsh environments. In this review, the recent progress in SiC-based synaptic devices is summarized. Firstly, an in-depth discussion is conducted regarding the categories, working mechanisms, and structural designs of these devices. Subsequently, several application scenarios for SiC-based synaptic devices are presented. Finally, a few perspectives and directions for their future development are outlined.

Optoelectronic memristor is generating growing research interest for high efficient computing and sensing-memory applications. In this work, an optoelectronic memristor with Au/a-C:Te/Pt structure is developed. Synaptic functions, i.e., excitatory post-synaptic current and pair-pulse facilitation are successfully mimicked with the memristor under electrical and optical stimulations. More importantly, the device exhibited distinguishable response currents by adjusting 4-bit input electrical/optical signals. A multi-mode reservoir computing (RC) system is constructed with the optoelectronic memristors to emulate human tactile-visual fusion recognition and an accuracy of 98.7% is achieved. The optoelectronic memristor provides potential for developing multi-mode RC system.

In this data explosion era, ensuring the secure storage, access, and transmission of information is imperative, encompassing all aspects ranging from safeguarding personal devices to formulating national information security strategies. Leveraging the potential offered by dual-type carriers for transportation and employing optical modulation techniques to develop high reconfigurable ambipolar optoelectronic transistors enables effective implementation of information destruction after reading, thereby guaranteeing data security. In this study, a reconfigurable ambipolar optoelectronic synaptic transistor based on poly (3-hexylthiophene) (P3HT) and poly [[N,N-bis(2-octyldodecyl)-napthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)] (N2200) blend film was fabricated through solution-processed method. The resulting transistor exhibited a relatively large ON/OFF ratio of 103 in both n- and p-type regions, and tunable photoconductivity after light illumination, particularly with green light. The photo-generated carriers could be effectively trapped under the gate bias, indicating its potential application in mimicking synaptic behaviors. Furthermore, the synaptic plasticity, including volatile/non?volatile and excitatory/inhibitory characteristics, could be finely modulated by electrical and optical stimuli. These optoelectronic reconfigurable properties enable the realization of information light assisted burn after reading. This study not only offers valuable insights for the advancement of high-performance ambipolar organic optoelectronic synaptic transistors but also presents innovative ideas for the future information security access systems.

Photonic neural networks have garnered significant attention in recent years due to their ultra-high computational speed, broad bandwidth, and parallel processing capabilities. However, compared to conventional electronic nonlinear activation function (NAF), progress on efficient and easily implementable optical nonlinear activation function (ONAF) was barely reported. To address this issue, we proposed a programmable, low-loss ONAF device based on a silicon micro-ring resonator capped with the Antimony selenide (Sb2Se3) thin films, and with indium tin oxide (ITO) used as the microheater. Leveraging our self-developed phase-transformation kinetic and optical models, we successfully simulated the phase-transition behavior of Sb2Se3 and three different ONAFs—ELU, ReLU, and radial basis function (RBF) were achieved according to discernible optical responses of proposed devices under different phase-change extents. Classification results from the Fashion MNIST dataset demonstrated that these ONAFs can be considered as appropriate substitutes for traditional NAF. This indicated the bright prospect of the proposed device for nonlinear activation function in future photonic neural networks.

The traditional von Neumann architecture has demonstrated inefficiencies in parallel computing and adaptive learning, rendering it incapable of meeting the growing demand for efficient and high-speed computing. Neuromorphic computing with significant advantages such as high parallelism and ultra-low power consumption is regarded as a promising pathway to overcome the limitations of conventional computers and achieve the next-generation artificial intelligence. Among various neuromorphic devices, the artificial synapses based on electrolyte-gated transistors stand out due to their low energy consumption, multimodal sensing/recording capabilities, and multifunctional integration. Moreover, the emerging optoelectronic neuromorphic devices which combine the strengths of photonics and electronics have demonstrated substantial potential in the neuromorphic computing field. Therefore, this article reviews recent advancements in electrolyte-gated optoelectronic neuromorphic transistors. First, it provides an overview of artificial optoelectronic synapses and neurons, discussing aspects such as device structures, operating mechanisms, and neuromorphic functionalities. Next, the potential applications of optoelectronic synapses in different areas such as artificial visual system, pain system, and tactile perception systems are elaborated. Finally, the current challenges are summarized, and future directions for their developments are proposed.

In recent years, research focusing on synaptic device based on phototransistors has provided a new method for associative learning and neuromorphic computing. A TiO2/AlGaN/GaN heterostructure-based synaptic phototransistor is fabricated and measured, integrating a TiO2 nanolayer gate and a two-dimensional electron gas (2DEG) channel to mimic the synaptic weight and the synaptic cleft, respectively. The maximum drain to source current is 10 nA, while the device is driven at a reverse bias not exceeding ?2.5 V. A excitatory postsynaptic current (EPSC) of 200 nA can be triggered by a 365 nm UVA light spike with the duration of 1 s at light intensity of 1.35 μW?cm?2. Multiple synaptic neuromorphic functions, including EPSC, short-term/long-term plasticity (STP/LTP) and paried-pulse facilitation (PPF), are effectively mimicked by our GaN-based heterostructure synaptic device. In the typical Pavlov’s dog experiment, we demonstrate that the device can achieve "retraining" process to extend memory time through enhancing the intensity of synaptic weight, which is similar to the working mechanism of human brain.

The hierarchical and coordinated processing of visual information by the brain demonstrates its superior ability to minimize energy consumption and maximize signal transmission efficiency. Therefore, it is crucial to develop artificial visual synapses that integrate optical sensing and synaptic functions. This study fully leverages the excellent photoresponsivity properties of the PM6 : Y6 system to construct a vertical photo-tunable organic memristor and conducts in-depth research on its resistive switching performance, photodetection capability, and simulation of photo-synaptic behavior, showcasing its excellent performance in processing visual information and simulating neuromorphic behaviors. The device achieves stable and gradual resistance change, successfully simulating voltage-controlled long-term potentiation/depression (LTP/LTD), and exhibits various photo-electric synergistic regulation of synaptic plasticity. Moreover, the device has successfully simulated the image perception and recognition functions of the human visual nervous system. The non-volatile Au/PM6 : Y6/ITO memristor is used as an artificial synapse and neuron modeling, building a hierarchical coordinated processing SLP-CNN cascade neural network for visual image recognition training, its linear tunable photoconductivity characteristic serves as the weight update of the network, achieving a recognition accuracy of up to 93.4%. Compared with the single-layer visual target recognition model, this scheme has improved the recognition accuracy by 19.2%.

Memristors have a synapse-like two-terminal structure and electrical properties, which are widely used in the construction of artificial synapses. However, compared to inorganic materials, organic materials are rarely used for artificial spiking synapses due to their relatively poor memrisitve performance. Here, for the first time, we present an organic memristor based on an electropolymerized dopamine-based memristive layer. This polydopamine-based memristor demonstrates the improvements in key performance, including a low threshold voltage of 0.3 V, a thin thickness of 16 nm, and a high parasitic capacitance of about 1 μF?mm?2. By leveraging these properties in combination with its stable threshold switching behavior, we construct a capacitor-free and low-power artificial spiking neuron capable of outputting the oscillation voltage, whose spiking frequency increases with the increase of current stimulation analogous to a biological neuron. The experimental results indicate that our artificial spiking neuron holds potential for applications in neuromorphic computing and systems.

Synaptic nano-devices have powerful capabilities in logic, memory and learning, making them essential components for constructing brain-like neuromorphic computing systems. Here, we have successfully developed and demonstrated a synaptic nano-device based on Ga2O3 nanowires with low energy consumption. Under 255 nm light stimulation, the biomimetic synaptic nano-device can stimulate various functionalities of biological synapses, including pulse facilitation, peak time-dependent plasticity and memory learning ability. It is found that the artificial synaptic device based on Ga2O3 nanowires can achieve an excellent "learning?forgetting?relearning" functionality. The transition from short-term memory to long-term memory and retention of the memory level after the stepwise learning can attribute to the great relearning functionality of Ga2O3 nanowires. Furthermore, the energy consumption of the synaptic nano-device can be lower than 2.39 × 10?11 J for a synaptic event. Moreover, our device demonstrates exceptional stability in long-term stimulation and storage. In the application of neural morphological computation, the accuracy of digit recognition exceeds 90% after 12 training sessions, indicating the strong learning capability of the cognitive system composed of this synaptic nano-device. Therefore, our work paves an effective way for advancing hardware-based neural morphological computation and artificial intelligence systems requiring low power consumption.

Implantable temperature sensors are revolutionizing physiological monitoring and playing a crucial role in diagnostics, therapeutics, and life sciences research. This review classifies the materials used in these sensors into three categories: metal-based, inorganic semiconductor, and organic semiconductor materials. Metal-based materials are widely used in medical and industrial applications due to their linearity, stability, and reliability. Inorganic semiconductors provide rapid response times and high miniaturization potential, making them promising for biomedical and environmental monitoring. Organic semiconductors offer high sensitivity and ease of processing, enabling the development of flexible and stretchable sensors. This review analyzes recent studies for each material type, covering design principles, performance characteristics, and applications, highlighting key advantages and challenges regarding miniaturization, sensitivity, response time, and biocompatibility. Furthermore, critical performance parameters of implantable temperature sensors based on different material types are summarized, providing valuable references for future sensor design and optimization. The future development of implantable temperature sensors is discussed, focusing on improving biocompatibility, long-term stability, and multifunctional integration. These advancements are expected to expand the application potential of implantable sensors in telemedicine and dynamic physiological monitoring.

Photodetectors with weak-light detection capabilities play an indispensable role in various crucial fields such as health monitors, imaging, optical communication, and etc. Nevertheless, the detection of weak light signals is often severely interfered by multiple factors such as background light, dark noise and circuit noise, making it difficult to accurately capture signals. While traditional technologies like silicon photomultiplier tubes excel in sensitivity, their high cost and inherent fragility restrict their widespread application. Against this background, perovskite materials have rapidly emerged as a research focus in the field of photodetection due to their simple preparation processes and exceptional optoelectronic properties. Not only are the preparation processes of perovskite materials straightforward and cost-effective, but more importantly, they can be flexibly integrated into flexible and stretchable substrates. This characteristic significantly compensates for the shortcomings of traditional rigid electronic devices in specific application scenarios, opening up entirely new possibilities for photodetection technology. Herein, recent advances in perovskite light detection technology are reviewed. Firstly, the chemical and physical properties of perovskite materials are discussed, highlighting their remarkable advantages in weak-light detection. Subsequently, the review systematically organizes various preparation techniques of perovskite materials and analyses their advantages in different application scenarios. Meanwhile, from the two core dimensions of performance improvement and light absorption enhancement, the key strategies of improving the performance of perovskite weak-light photodetectors are explored. Finally, the review concludes with a brief summary and a discussion on the potential challenges that may arise in the further development of perovskite devices.

With the rapid development of the internet of things (IoT) and wearable electronics, the role of flexible sensors is becoming increasingly irreplaceable, due to their ability to process and convert information acquisition. Two-dimensional (2D) materials have been widely welcomed by researchers as sensitive layers, which broadens the range and application of flexible sensors due to the advantages of their large specific surface area, tunable energy bands, controllable thickness at the atomic level, stable mechanical properties, and excellent optoelectronic properties. This review focuses on five different types of 2D materials for monitoring pressure, humidity, sound, gas, and so on, to realize the recognition and conversion of human body and environmental signals. Meanwhile, the main problems and possible solutions of flexible sensors based on 2D materials as sensitive layers are summarized.

Multimodal sensor fusion can make full use of the advantages of various sensors, make up for the shortcomings of a single sensor, achieve information verification or information security through information redundancy, and improve the reliability and safety of the system. Artificial intelligence (AI), referring to the simulation of human intelligence in machines that are programmed to think and learn like humans, represents a pivotal frontier in modern scientific research. With the continuous development and promotion of AI technology in Sensor 4.0 age, multimodal sensor fusion is becoming more and more intelligent and automated, and is expected to go further in the future. With this context, this review article takes a comprehensive look at the recent progress on AI-enhanced multimodal sensors and their integrated devices and systems. Based on the concept and principle of sensor technologies and AI algorithms, the theoretical underpinnings, technological breakthroughs, and pragmatic applications of AI-enhanced multimodal sensors in various fields such as robotics, healthcare, and environmental monitoring are highlighted. Through a comparative study of the dual/tri-modal sensors with and without using AI technologies (especially machine learning and deep learning), AI-enhanced multimodal sensors highlight the potential of AI to improve sensor performance, data processing, and decision-making capabilities. Furthermore, the review analyzes the challenges and opportunities afforded by AI-enhanced multimodal sensors, and offers a prospective outlook on the forthcoming advancements.

The rapid advancement of information technology has heightened interest in complementary devices and circuits. Conventional p-type semiconductors often lack sufficient electrical performance, thus prompting the search for new materials with high hole mobility and long-term stability. Elemental tellurium (Te), featuring a one-dimensional chiral atomic structure, has emerged as a promising candidate due to its narrow bandgap, high hole mobility, and versatility in industrial applications, particularly in electronics and renewable energy. This review highlights recent progress in Te nanostructures and related devices, focusing on synthesis methods, including vapor deposition and hydrothermal synthesis, which produce Te nanowires, nanorods, and other nanostructures. Critical applications in photodetectors, gas sensors, and energy harvesting devices are discussed, with a special emphasis on their role within the internet of things (IoT) framework, a rapidly growing field that is reshaping our technological landscape. The prospects and potential applications of Te-based technologies are also highlighted.

Organic electrochemical transistors have emerged as a solution for artificial synapses that mimic the neural functions of the brain structure, holding great potentials to break the bottleneck of von Neumann architectures. However, current artificial synapses rely primarily on electrical signals, and little attention has been paid to the vital role of neurotransmitter-mediated artificial synapses. Dopamine is a key neurotransmitter associated with emotion regulation and cognitive processes that needs to be monitored in real time to advance the development of disease diagnostics and neuroscience. To provide insights into the development of artificial synapses with neurotransmitter involvement, this review proposes three steps towards future biomimic and bioinspired neuromorphic systems. We first summarize OECT-based dopamine detection devices, and then review advances in neurotransmitter-mediated artificial synapses and resultant advanced neuromorphic systems. Finally, by exploring the challenges and opportunities related to such neuromorphic systems, we provide a perspective on the future development of biomimetic and bioinspired neuromorphic systems.

Infrared optoelectronic sensing is the core of many critical applications such as night vision, health and medication, military, space exploration, etc. Further including mechanical flexibility as a new dimension enables novel features of adaptability and conformability, promising for developing next-generation optoelectronic sensory applications toward reduced size, weight, price, power consumption, and enhanced performance (SWaP3). However, in this emerging research frontier, challenges persist in simultaneously achieving high infrared response and good mechanical deformability in devices and integrated systems. Therefore, we perform a comprehensive review of the design strategies and insights of flexible infrared optoelectronic sensors, including the fundamentals of infrared photodetectors, selection of materials and device architectures, fabrication techniques and design strategies, and the discussion of architectural and functional integration towards applications in wearable optoelectronics and advanced image sensing. Finally, this article offers insights into future directions to practically realize the ultra-high performance and smart sensors enabled by infrared-sensitive materials, covering challenges in materials development and device micro-/nanofabrication. Benchmarks for scaling these techniques across fabrication, performance, and integration are presented, alongside perspectives on potential applications in medication and health, biomimetic vision, and neuromorphic sensory systems, etc.

With the rapid development of artificial intelligence (AI) technology, the demand for high-performance and energy-efficient computing is increasingly growing. The limitations of the traditional von Neumann computing architecture have prompted researchers to explore neuromorphic computing as a solution. Neuromorphic computing mimics the working principles of the human brain, characterized by high efficiency, low energy consumption, and strong fault tolerance, providing a hardware foundation for the development of new generation AI technology. Artificial neurons and synapses are the two core components of neuromorphic computing systems. Artificial perception is a crucial aspect of neuromorphic computing, where artificial sensory neurons play an irreplaceable role thus becoming a frontier and hot topic of research. This work reviews recent advances in artificial sensory neurons and their applications. First, biological sensory neurons are briefly described. Then, different types of artificial neurons, such as transistor neurons and memristive neurons, are discussed in detail, focusing on their device structures and working mechanisms. Next, the research progress of artificial sensory neurons and their applications in artificial perception systems is systematically elaborated, covering various sensory types, including vision, touch, hearing, taste, and smell. Finally, challenges faced by artificial sensory neurons at both device and system levels are summarized.

Artificial skin should embody a softly functional film that is capable of self-powering, healing and sensing with neuromorphic processing. However, the pursuit of a bionic skin that combines high flexibility, self-healability, and zero-powered photosynaptic functionality remains elusive. In this study, we report a self-powered and self-healable neuromorphic vision skin, featuring silver nanoparticle-doped ionogel heterostructure as photoacceptor. The localized surface plasmon resonance induced by light in the nanoparticles triggers temperature fluctuations within the heterojunction, facilitating ion migration for visual sensing with synaptic behaviors. The abundant reversible hydrogen bonds in the ionogel endow the skin with remarkable mechanical flexibility and self-healing properties. We assembled a neuromorphic visual skin equipped with a 5 × 5 photosynapse array, capable of sensing and memorizing diverse light patterns.

We demonstrate a bipolar graphene/F16CuPc synaptic transistor (GFST) with matched p-type and n-type bipolar properties, which emulates multiplexed neurotransmission of the release of two excitatory neurotransmitters in graphene and F16CuPc channels, separately. This process facilitates fast-switching plasticity by altering charge carriers in the separated channels. The complementary neural network for image recognition of Fashion-MNIST dataset was constructed using the matched relative amplitude and plasticity properties of the GFST dominated by holes or electrons to improve the weight regulation and recognition accuracy, achieving a pattern recognition accuracy of 83.23%. These results provide new insights to the construction of future neuromorphic systems.

Exploring electrode materials with larger capacity, higher power density and longer cycle life was critical for developing advanced flexible lithium-ion batteries (LIBs). Herein, we used a controlled two-step method including electrospraying followed with calcination treatment by CVD furnace to design novel electrodes of Si/Six/C and Sn/C microrods array consisting of nanospheres on flexible carbon cloth substrate (denoted as Si/Six/C@CC, Sn/C@CC). Microrods composed of cumulated nanospheres (the diameter was approximately 120 nm) had a mean diameter of approximately 1.5 μm and a length of around 4.0 μm, distributing uniformly along the entire woven carbon fibers. Both of Si/Si/Six/C@CC and Sn/C@CC products were synthesized as binder-free anodes for Li-ion battery with the features of high reversible capacity and excellent cycling. Especially Si/Six/C electrode exhibited high specific capacity of about 1750 mA?h?g?1 at 0.5 A?g?1 and excellent cycling ability even after 1050 cycles with a capacity of 1388 mA?h?g?1. Highly flexible Si/Six/C@CC//LiCoO2 batteries based on liquid and solid electrolytes were also fabricated, exhibiting high flexibility, excellent electrical stability and potential applications in flexible wearable electronics.

In the era of Metaverse and virtual reality (VR)/augmented reality (AR), capturing finger motion and force interactions is crucial for immersive human-machine interfaces. This study introduces a flexible electronic skin for the index finger, addressing coupled perception of both state and process in dynamic tactile sensing. The device integrates resistive and giant magnetoelastic sensors, enabling detection of surface pressure and finger joint bending. This e-skin identifies three phases of finger action: bending state, dynamic normal force and tangential force (sweeping). The system comprises resistive carbon nanotubes (CNT)/polydimethylsiloxane (PDMS) films for bending sensing and magnetoelastic sensors (NdFeB particles, EcoFlex, and flexible coils) for pressure detection. The inward bending resistive sensor, based on self-assembled microstructures, exhibits directional specificity with a response time under 120 ms and bending sensitivity from 0° to 120°. The magnetoelastic sensors demonstrate specific responses to frequency and deformation magnitude, as well as sensitivity to surface roughness during sliding and material hardness. The system’s capability is demonstrated through tactile-based bread type and condition recognition, achieving 92% accuracy. This intelligent patch shows broad potential in enhancing interactions across various fields, from VR/AR interfaces and medical diagnostics to smart manufacturing and industrial automation.

Heart rate variability (HRV) that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system (ANS) has attracted considerable attention. However, traditional electrocardiogram (ECG) devices for HRV analysis are bulky, and hard wires are needed to attach measuring electrodes to the chest, resulting in the poor wearable experience during the long-term measurement. Compared with that, wearable electronics enabling continuously cardiac signals monitoring and HRV assessment provide a desirable and promising approach for helping subjects determine sleeping issues, cardiovascular diseases, or other threats to physical and mental well-being. Until now, significant progress and advances have been achieved in wearable electronics for HRV monitoring and applications for predicting human physical and mental well-being. In this review, the latest progress in the integration of wearable electronics and HRV analysis as well as practical applications in assessment of human physical and mental health are included. The commonly used methods and physiological signals for HRV analysis are briefly summarized. Furthermore, we highlighted the research on wearable electronics concerning HRV assessment and diverse applications such as stress estimation, drowsiness detection, etc. Lastly, the current limitations of the integrated wearable HRV system are concluded, and possible solutions in such a research direction are outlined.

The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment. Major atmospheric pollutants include NO2 and CO2. Hence, it is imperative to develop NO2 and CO2 sensors for ambient conditions, that can be used in indoor air quality monitoring, breath analysis, food spoilage detection, etc. In the present study, two thin film nanocomposite (nickel oxide-graphene and nickel oxide-silver nanowires) gas sensors are fabricated using direct ink writing. The nano-composites are investigated for their structural, optical, and electrical properties. Later the nano-composite is deposited on the interdigitated electrode (IDE) pattern to form NO2 and CO2 sensors. The deposited films are then exposed to NO2 and CO2 gases separately and their response and recovery times are determined using a custom-built gas sensing setup. Nickel oxide-graphene provides a good response time and recovery time of 10 and 9 s, respectively for NO2, due to the higher electron affinity of graphene towards NO2. Nickel oxide-silver nanowire nano-composite is suited for CO2 gas because silver is an excellent electrocatalyst for CO2 by giving response and recovery times of 11 s each. This is the first report showcasing NiO nano-composites for NO2 and CO2 sensing at room temperature.

Flexible photodetectors have garnered significant attention by virtue of their potential applications in environmental monitoring, wearable healthcare, imaging sensing, and portable optical communications. Perovskites stand out as particularly promising materials for photodetectors, offering exceptional optoelectronic properties, tunable band gaps, low-temperature solution processing, and notable mechanical flexibility. In this review, we explore the latest progress in flexible perovskite photodetectors, emphasizing the strategies developed for photoactive materials and device structures to enhance optoelectronic performance and stability. Additionally, we discuss typical applications of these devices and offer insights into future directions and potential applications.

With the advancement of artificial intelligence, optic in-sensing reservoir computing based on emerging semiconductor devices is high desirable for real-time analog signal processing. Here, we disclose a flexible optomemristor based on C27H30O15/FeOx heterostructure that presents a highly sensitive to the light stimuli and artificial optic synaptic features such as short- and long-term plasticity (STP and LTP), enabling the developed optomemristor to implement complex analogy signal processing through building a real-physical dynamic-based in-sensing reservoir computing algorithm and yielding an accuracy of 94.88% for speech recognition. The charge trapping and detrapping mediated by the optic active layer of C27H30O15 that is extracted from the lotus flower is response for the positive photoconductance memory in the prepared optomemristor. This work provides a feasible organic?inorganic heterostructure as well as an optic in-sensing vision computing for an advanced optic computing system in future complex signal processing.

Owing to the unique characteristics of ultra-thin body and nanoscale sensitivity volume, MoS2-based field-effect transistors (FETs) are regarded as optimal components for radiation-hardened integrated circuits (ICs), which is exponentially growing demanded especially in the fields of space exploration and the nuclear industry. Many researches on MoS2-based radiation tolerance electronics focused on the total ionizing dose (TID) effect, while few works concerned the displacement damage (DD) effects, which is more challenging to measure and more crucial for practical applications. We first conducted measurements to assess the DD effects of MoS2 FETs, and then presented the stopping and ranges of ions in matter (SRIM) simulation to analysis the DD degradation mechanism in MoS2 electronics. The monolayer MoS2-based FETs exhibit DD radiation tolerance up to 1.56 × 1013 MeV/g, which is at least two order of magnitude than that in conventional radiation hardened ICs. The exceptional DD radiation tolerance will significantly enhance the deployment of MoS2 integrated circuits in environments characterized by high-energy solar and cosmic radiation exposure.

Recently, there has been considerable interest in high-efficiency ultraviolet (UV) photodetectors for their potential practical uses. In this study, a high-quality UV photodetector was fabricated using a combination of Ag and Au NPs with GaN film. The GaN film was deposited using sputtering technique, whereas Ag and Au films were grown using thermal evaporation technique. Ag?Au bimetallic nanoparticles were formed by treating them at the various annealing temperature to improve the interaction between light and the photoactive layers of the photodetectors. The optimal annealing temperature to achieve the best performance of a photodetector is 650 °C. This led to a photoresponsivity of 98.5 A/W and the ON/OFF ratio of 705 at low bias voltage of 1 V. This work establishes the foundation for the advancement of high-performance UV photodetectors.

Simulating the human olfactory nervous system is one of the key issues in the field of neuromorphic computing. Olfactory neurons interact with gas molecules, transmitting and storing odor information to the olfactory center of the brain. In order to emulate the complex functionalities of olfactory neurons, this study presents a flexible olfactory synapse transistor (OST) based on pentacene/C8-BTBT organic heterojunction. By modulating the interface between the energy bands of the organic semiconductor layers, this device demonstrates high sensitivity (ppb level) and memory function for NH3 sensing. Typical synaptic behaviors triggered by NH3 pulses have been successfully demonstrated, such as inhibitory postsynaptic currents (IPSC), paired-pulse depression (PPD), long-term potentiation/depression (LTP/LTD), and transition from short-term depression (STD) to long-term depression (LTD). Furthermore, this device maintains stable olfactory synaptic functions even under different bending conditions, which can present new insights and possibilities for flexible synaptic systems and bio-inspired electronic products.

Graphene oxide, as a 2D material with nanometer thickness, offers ultra-high mobility, chaotic properties, and low cost. These make graphene oxide memristors beneficial for reservoir computing (RC) networks. In this study, continuous-wave (CW) laser processing is used to reduce chaotic graphene oxide (CGO) films, resulting in the non-volatile storage capability based on the reduced chaotic graphene oxide (rCGO) films. Laser power significantly impacts the characteristics of the rCGO memristor. Material characterization indicates that laser radiation can effectively reduce the oxygen content in CGO films. With optimized laser power, the rCGO memristor achieves a large ratio at 18 mW laser power. Benefiting from the short-term memory characteristics, distinct conductive states are achieved, which are further utilized to construct RC networks. With a third control probe, the rCGO memristor can express rich reservoir states, demonstrating accuracy in predicting the Hénon map with an NRMSE below 0.3. These findings provide the potential for developing flexible RC networks based on graphene oxide memristors via laser processing.

Ge/SiGe heterostructure quantum wells play a pivotal role in the pursuit of scalable silicon-based qubits. The varying compressive strains within these quantum wells profoundly influence the physical characteristics of the qubits, yet this factor remains largely unexplored, driving our research endeavor. In this study, we utilized RP-CVD (Reduced Pressure Chemical Vapor Deposition) to grow Ge quantum wells with varied compressive strain, proposing growth schemes for lightly-strained (ε∥ = ?0.43%) QW (quantum well), standard-strained (ε∥ = ?0.61%) QW, and heavily-strained (ε∥ = ?1.19%) QW. Through comprehensive material characterization, particularly employing the low-temperature magneto-transport measurements, we derived the percolation densities ranging from 4.7 × 1010 to 14.2 × 1010 cm?2 and mobilities from 3.382 × 105 to 7.301 × 105 cm2?V?1?s?1. Combined with the first-principles calculations, our analysis delves into the trends in effective mass and percolation density at low temperatures, shedding light on the impact of quantum effects on band structures and the interplay between structural components and wave functions. This research offers a comprehensive investigation into the intrinsic mechanisms governing complex multi-strained quantum wells, spanning growth, characterization, and computational perspectives, thereby establishing a strategy for the growth of high-quality strained quantum wells.

The advanced fin-shaped field-effect transistor (FinFET) technology offers higher integration density and stronger channel control capabilities, however, more complex process effects are also introduced which have significant influence on device performance. To address these issues, we complete a design-technology co-optimization (DTCO) focused on FinFET, including both process-induced effect during gate formation and corresponding digital unit optimization design. The 14 nm FinFET complementary metal oxide semiconductor (CMOS) technology is used to illustrate the sensitivity of transistor performance to process-induced effect, specifically the poly pitch effect (PPE) and cut poly effect (CPE). Predictive technology computer aided design (TCAD) simulations have been carried out to evaluate the transistor performance in advance. Based on the results, optimizations in digital unit design is proposed. Fall delay of the digital unit inverter is decreased by 0.7%, and the rise delay is decreased by 2.1%. For multiple selector (MUX2NV), the delay decreases by 4.64% for rise and 3.56% for drop, respectively.

Triboelectric nanogenerator (TENG) utilizing tribovoltaic effect can directly produce direct current with high energy conversion efficiency, which expands their application in semiconductor devices and self-powered systems. This work comprehensively summarizes the recent developments in semiconductor-based direct current TENGs (SDC-TENGs), which hold significant promise for DC energy harvesting technologies and semiconductor systems. First, the tribovoltaic effect is elucidated, and SDC-TENGs are categorized into six types based on different triboelectric structures: metal?semiconductor (M?S), metal?insulator?semiconductor (M?I?S), semiconductor?semiconductor (S?S), semiconductor?insulator?semiconductor (S?I?S), liquid?semiconductor (L?S), and metal/semiconductor?liquid?semiconductor (M/S?L?S) contact devices. Subsequent sections detail the operational mechanisms, strengths, and limitations of each category. Additionally, this paper outlines the enhancement mechanisms of SDC-TENGs providing guidance and recommendations for performance improvement. The conclusion highlights potential application scenarios for various types of SDC-TENGs, outlining the prospective benefits and challenges. SDC-TENG technology is poised to drive revolutionary developments in semiconductor devices and self-powered systems.

Human skin, through its complex mechanoreceptor system, possesses the exceptional ability to finely perceive and differentiate multimodal mechanical stimuli, forming the biological foundation for dexterous manipulation, environmental exploration, and tactile perception. Tactile sensors that emulate this sensory capability, particularly in the detection, decoupling, and application of normal and shear forces, have made significant strides in recent years. This review comprehensively examines the latest research advancements in tactile sensors for normal and shear force sensing, delving into the design and decoupling methods of multi-unit structures, multilayer encapsulation structures, and bionic structures. It analyzes the advantages and disadvantages of various sensing principles, including piezoresistive, capacitive, and self-powered mechanisms, and evaluates their application potential in health monitoring, robotics, wearable devices, smart prosthetics, and human-machine interaction. By systematically summarizing current research progress and technical challenges, this review aims to provide forward-looking insights into future research directions, driving the development of electronic skin technology to ultimately achieve tactile perception capabilities comparable to human skin.

In this study, aluminum-doped zinc oxide (AZO) thin films were deposited onto a low-temperature polyethylene terephthalate (PET) substrate using DC magnetron sputtering. Deposition parameters included power range of 100?300 W, a working pressure of 15 mTorr, and a substrate temperature of 50 °C. Post-deposition, flash lamp annealing (FLA) was employed as a rapid thermal processing method with a pulse duration of 1.7 ms and energy density of 7 J·cm?2, aimed at enhancing the film's quality while preserving the temperature-sensitive PET substrate. FLA offers advantages over conventional annealing, including shorter processing times and improved material properties. The structural, optical, and electrical characteristics of the AZO films were assessed using X-ray diffraction, field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, ultraviolet?visible spectroscopy, and Hall effect measurements. The results demonstrated that properties of AZO films varied with deposition and annealing conditions. Films deposited at 200 W and subjected to FLA exhibited superior crystallinity, with average visible light transmittance exceeding 80% and resistivity as low as 0.38 Ω·cm representing 95% improvement in transmittance. Electrical analysis revealed that carrier concentration, mobility, and resistivity were influenced by both sputtering and annealing parameters. These findings underscore the effectiveness of FLA in optimizing AZO thin film properties, highlighting potential in optoelectronics applications.

Frequency combs with equally spaced frequency lines show great potentials for applications in spectroscopy, imaging, communications, and so on. In the terahertz frequency region, the quantum cascade laser (QCL) is an ideal radiation source for frequency comb and dual-comb operation. The systematic evaluation of phase noise characteristics of terahertz QCL frequency comb and dual-comb sources is of great importance for high precision measurements. In this work, we present detailed measurements and analysis of the phase noise characteristics of terahertz QCL frequency comb and dual-comb sources emitting around 4.2 THz with repetition frequencies of ~6.2 GHz. The measurement results for the current noise of the direct current (DC) sources (that are used to electrically pump the terahertz QCLs) indicate that at 100 Hz, the current noise for DC-1 and DC-2 is 0.3895 and 0.0982 nA/Hz1/2, respectively. Such levels of current noise can be safely disregarded. The phase noise of radio frequency (RF) generators (that are employed for injection locking and phase locking), intermode beatnotes, and dual-comb signals with and without phase-locked loop (PLL) are all measured and compared. The experimental results show that in the free-running mode, the phase noise of the intermode beatnote signals is always lower than that of the dual-comb signals across all frequencies. Additionally, the phase noise induced by the RF generators is negligible. By employing the phase locking technique, the phase noise of the intermode beatnote and dual-comb signals in the low offset frequency band can be significantly suppressed. At an offset frequency of 100 Hz, the measured phase noise values of the dual-comb line without and with phase locking are 15.026 and ?64.801 dBc/Hz, respectively.

Low-resistance Ohmic contact is critical for the high efficiency GaN-based laser diodes. This study investigates the introduction of the In0.15Ga0.85N contact layer on the specific contact resistance. Experimental results reveal that adopting the In0.15Ga0.85N contact layer yields a minimized specific contact resistance of 2.57 × 10?5 Ω·cm2 which is two orders of magnitude lower than the GaN contact layer (7.61 × 10?3 Ω·cm2). A decrease in the specific contact resistance arises from the reduction of the barrier between the metal and p-type In0.15Ga0.85N. To develop an optimal metal electrode combination on the In0.15Ga0.85N contact layer, the Pd/Au and Ni/Au electrode stacks which are most commonly used in the formation of Ohmic contact with p-GaN are investigated. Metal stack of 10/30 nm Pd/Au is demonstrated effective in reducing the specific contact resistance to 10?5 Ω·cm2 level. The mechanism of the variation of the specific contact resistance under different annealing atmospheres is explained by auger electron spectroscopy.

This study presents a comprehensive optimization and comparative analysis of thermoelectric (TE) infrared (IR) detectors using Bi2Te3 and Si materials. Through theoretical modeling and numerical simulations, we explored the impact of TE material properties, device structure, and operating conditions on responsivity, detectivity, noise equivalent temperature difference (NETD), and noise equivalent power (NEP). Our study offers an optimally designed IR detector with responsivity and detectivity approaching 2 × 105 V/W and 6 × 109 cm?Hz1/2/W, respectively. This enhancement is attributed to unique design features, including raised thermal collectors and long suspended thin thermoelectric wire sensing elements embedded in low thermal conductivity organic materials like parylene. Moreover, we demonstrate the compatibility of Bi2Te3-based detector fabrication processes with existing MEMS foundry processes, facilitating scalability and manufacturability. Importantly, for TE IR detectors, zT/κ emerges as a critical parameter contrary to conventional TE material selection based solely on zT (where zT is the thermoelectric figure of merit and κ is the thermal conductivity).

This paper presents a comprehensive analysis of the short-circuit failure mechanisms in commercial 1.2 kV planar silicon carbide (SiC) metal–oxide–semiconductor field-effect transistors (MOSFETs) under 400 and 800 V bus voltage conditions. The study compares two products with varying short-circuit tolerances, scrutinizing their external characteristics and intrinsic factors that influence their short-circuit endurance. Experimental and numerical analyses reveal that at 400 V, the differential thermal expansion between the source metal and the dielectric leads to cracking, which in turn facilitates the infiltration of liquid metal and results in a gate–source short circuit. At 800 V, the failure mechanism is markedly different, attributed to the thermal carrier effect leading to the degradation of the gate oxide, which impedes the device's capacity to switch off, thereby triggering thermal runaway. The paper proposes strategies to augment the short-circuit robustness of SiC MOSFETs at both voltage levels, with the objective of fortifying the device's resistance to such failures.

In this work, a PEDOT:PSS/Sn:α-Ga2O3 hybrid heterojunction diode (HJD) photodetector was fabricated by spin-coating highly conductive PEDOT:PSS aqueous solution on the mist chemical vapor deposition (Mist-CVD) grown Sn:α-Ga2O3 film. This approach provides a facile and low-cost p-PEDOT:PSS/n-Sn:α-Ga2O3 spin-coating method that facilitates self-powering performance through p?n junction formation. A typical type-Ⅰ heterojunction is formed at the interface of Sn:α-Ga2O3 film and PEDOT:PSS, and contributes to a significant photovoltaic effect with an open-circuit voltage (Voc) of 0.4 V under the 254 nm ultraviolet (UV) light. When operating in self-powered mode, the HJD exhibits excellent photo-response performance including an outstanding photo-current of 10.9 nA, a rapid rise/decay time of 0.38/0.28 s, and a large on/off ratio of 91.2. Additionally, the HJD also possesses excellent photo-detection performance with a high responsivity of 5.61 mA/W and a good detectivity of 1.15 × 1011 Jones at 0 V bias under 254 nm UV light illumination. Overall, this work may explore the potential range of self-powered and high-performance UV photodetectors.

In this study, we present an in-depth exploration of charge transport phenomena and variable photo-switching characteristics in a novel double-perovskite-based three-terminal device. The Cs2AgBiBr6 thin film (TF) was synthesized through a three-step thermal evaporation process followed by precise open-air annealing, ensuring superior film quality as confirmed by structural and morphological characterizations. Photoluminescence spectroscopy revealed distinct emissions at 2.28 and 2.07 eV, indicative of both direct and indirect electronic transitions. Our device exhibited space-charge limited current (SCLC) behaviour beyond 0.35 V, aligning with the relationship Current(I)∝Voltage (V)m, where the exponent m transitioned from ≤1 to >1. Detailed analysis of Schottky parameters within the trap-filled limit (TFL) regime was conducted, accounting for variations in temperature and optical power. Significantly, the self-powered photodetector demonstrated outstanding performance under illumination. The sensitivity of the device was finely tunable via the applied bias voltages at the third terminal. Notably, an optimal bias voltage of ±100 μV yielded maximum responsivity (R) of 0.48 A/W and an impressive detectivity (D*) of 1.07 × 109 Jones, highlighting the potential of this double-perovskite-based device for advanced optoelectronic applications.

Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure, which have potentially tunable optical, electronic, and electrical properties suitable for practical applications. Herein, we report an effective method for synthesizing mesocrystal zinc oxide nanorods (ZnONRs). The crystal, surface, and internal structures of the zinc oxide mesocrystals were fully characterized. Mesocrystal zinc oxide nanorods/reduced graphene oxide (ZnONRs/rGO) nanocomposite superstructure were synthesized also using the hydrothermal method. The crystal, surface, chemical, and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized. The optical absorption coefficient, bandgap energy, band structure, and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties. Finally, the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet (UV) photodetection applications. Finally, we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.

This paper presents the design, fabrication, packaging, and characterization of a high-performance CMUT array. The array, which features rectangular cells fabricated using a sacrificial release process, achieves a receiving sensitivity of ?231.44 dB (re: 1 V/μPa) with a 40 dB gain. Notably, the CMUT array exhibits a minimal sensitivity variation of just 0.87 dB across a temperature range of 0 to 60 °C. Furthermore, the output voltage non-linearity at 1 kHz is approximately 0.44%. These test results demonstrate that the reception performance of the 67-element CMUT array is superior to that of commercial transducers. The high performance and compact design of this CMUT array underscore its significant commercial potential for hydrophone applications.

The choices of proper dopants and doping sites significantly influence the doping efficiency. In this work, using doping in AlN as an example, we discuss how to choose dopants and doping sites in semiconductors to create shallow defect levels. By comparing the defect properties of CN, ON, MgAl, and SiAl in AlN and analyzing the pros and cons of different doping approaches from the aspects of size mismatch between dopant and host elements, electronegativity difference and perturbation to the band edge states after the substitution, we propose that MgAl and SiAl should be the best dopants and doping sites for p-type and n-type doping, respectively. Further first-principles calculations verify our predictions as these defects present lower formation energies and shallower defect levels. The defect charge distributions also show that the band edge states, which mainly consist of N- s and p orbitals, are less perturbed when Al is substituted, therefore, the derived defect states turn out to be delocalized, opposite to the situation when N is substituted. This approach of analyzing the band structure of the host material and choosing dopants and doping sites to minimize the perturbation on the host band structure is general and can provide reliable estimations for finding shallow defect levels in semiconductors.

Perovskites dominate the photovoltaic research community over the last two decades due to its very high absorption coefficient, electron and hole mobility. However, most of the reported solar cells constitute organic perovskites which offer very high efficiency but are highly unstable. Chalcogenide perovskites like BaZrS3, CaZrS3, etc. promise to be a perfect alternate owing to its high stability and mobilities. But, till now no stable photovoltaic device has been successfully fabricated using these materials and the existing challenges present in the synthesis of such perovskites are discussed. Also, the basic thermodynamic aspects that are essential for formation of BaZrS3 are discussed. An extensive review on the precedent literatures and the future direction in the BaZrS3 photovoltaic device research is clearly given.

In this study, we present the development of self-aligned p-channel GaN back gate injection transistors (SA-BGITs) that exhibit a high ON-state current. This achievement is primarily attributed to the conductivity modulation effect of the 2-D electron gas (2DEG, the back gate) beneath the 2-D hole gas (2DHG) channel. SA-BGITs with a gate length of 1 μm have achieved an impressive peak drain current (ID,MAX) of 9.9 mA/mm. The fabricated SA-BGITs also possess a threshold voltage of 0.15 V, an exceptionally minimal threshold hysteresis of 0.2 V, a high switching ratio of 107, and a reduced ON-resistance (RON) of 548 Ω·mm. Additionally, the SA-BGITs exhibit a steep sub-threshold swing (SS) of 173 mV/dec, further highlighting their suitability for integration into GaN logic circuits.

Pre-ohmic-annealing (POA) treatment of P-GaN/AlN/AlGaN epitaxy under N2 atmosphere was demonstrated to effectively achieve good p-type ohmic contact as well as decreased epitaxy sheet resistance. Ohmic contact resistance (Rc) extracted by transfer length method reduced from 38 to 23 Ω·mm with alleviated contact barrier height from 0.55 to 0.51 eV after POA treatment. X-ray photoelectron spectroscopy and Hall measurement confirmed that POA treatment was able to reduce surface state density and improve the hole concentration of p-GaN. Due to the decreased Rc and improved two-dimensional hole gas (2DHG) density, an outstanding-performance GaN E-mode p-channel MOSFET was successfully realized.

4H silicon carbide (4H-SiC) has gained a great success in high-power electronics, owing to its advantages of wide bandgap, high breakdown electric field strength, high carrier mobility, and high thermal conductivity. Considering the high carrier mobility and high stability of 4H-SiC, 4H-SiC has great potential in the field of photoelectrochemical (PEC) water splitting. In this work, we demonstrate the irradiation-resistant PEC water splitting based on nanoporous 4H-SiC arrays. A new two-step anodizing approach is adopted to prepare 4H-SiC nanoporous arrays with different porosity, that is, a constant low-voltage etching followed by a pulsed high-voltage etching. The constant-voltage etching and pulsed-voltage etching are adopted to control the diameter of the nanopores and the depth of the nanoporous arrays, respectively. It is found that the nanoporous arrays with medium porosity has the highest PEC current, because of the enhanced light absorption and the optimized transportation of charge carriers along the walls of the nanoporous arrays. The performance of the PEC water splitting of the nanoporous arrays is stable after the electron irradiation with the dose of 800 and 1600 kGy, which indicates that 4H-SiC nanoporous arrays has great potential in the PEC water splitting under harsh environments.

Superjunction (SJ) is one of the most innovative concepts in the field of power semiconductor devices and is often referred to as a "milestone" in power MOS. Its balanced charge field modulation mechanism breaks through the strong dependency between the doping concentration in the drift region and the breakdown voltage VB in conventional devices. This results in a reduction of the trade-off relationship between specific on-resistance Ron,sp and VB from the conventional Ron,sp∝VB2.5 to Ron,sp∝W?VB1.32, and even to Ron,sp∝W·VB1.03. As the exponential term coefficient decreases, Ron,sp decreases with the cell width W, exhibiting a development pattern reminiscent of "Moore’s Law". This paper provides an overview of the latest research developments in SJ power semiconductor devices. Firstly, it introduces the minimum specific on-resistance Ron,min theory of SJ devices, along with its combination with special effects like 3-D depletion and tunneling, discussing the development of Ron,min theory in the wide bandgap SJ field. Subsequently, it discusses the latest advancements in silicon-based and wide bandgap SJ power devices. Finally, it introduces the homogenization field (HOF) and high-K voltage-sustaining layers derived from the concept of SJ charge balance. SJ has made significant progress in device performance, reliability, and integration, and in the future, it will continue to evolve through deeper integration with different materials, processes, and packaging technologies, enhancing the overall performance of semiconductor power devices.

This paper introduces a pioneering application of secondary ion mass spectrometry (SIMS) for estimating the electronic properties of Pb1?xSnxTe, a compound categorized as a topological crystalline insulator. The proposed approach marks the first application of SIMS for such estimations and focuses on investigating variations in ionization probabilities and shifts in the energy distribution of secondary ions. The ionization probabilities are influenced by pivotal parameters such as the material's work function and electron affinity. The derivation of these parameters hinges upon the energy gap's positioning relative to the vacuum level for varying values of x within the Pb1?xSnxTe compound. The findings elucidate noteworthy alterations in SIMS signals, particularly near the critical point of band-gap closing.

Cryogenic oxide-confined vertical-cavity surface-emitting laser (VCSEL) has promising application in cryogenic optical interconnect for cryogenic computing. In this paper, we demonstrate a cryogenic 850-nm oxide-confined VCSEL at around 4 K. The cryogenic VCSEL with an optical oxide aperture of 6.5 μm in diameter can operate in single fundamental mode with a side-mode suppression-ratio of 36 dB at 3.6 K, and the fiber-coupled output power reaches 1 mW at 5 mA. The small signal modulation measurements at 298 and 292 K show the fabricated VCSEL has the potential to achieve a high modulation bandwidth at cryogenic temperature.

Electron spins confined in semiconductor quantum dots (QDs) are one of potential candidates for physical implementation of scalable quantum information processing technologies. Tunnel coupling based inter exchange interaction between QDs is crucial in achieving single-qubit manipulation, two-qubit gate, quantum communication and quantum simulation. This review first provides a theoretical perspective that surveys a general framework, including the Helter−London approach, the Hund−Mulliken approach, and the Hubbard model, to describe the inter exchange interactions between semiconductor quantum dots. An electrical method to control the inter exchange interaction in a realistic device is proposed as well. Then the significant achievements of inter exchange interaction in manipulating single qubits, achieving two-qubit gates, performing quantum communication and quantum simulation are reviewed. The last part is a summary of this review.

In semiconductor photocatalysts, the easy recombination of photogenerated carriers seriously affects the application of photocatalytic materials in water treatment. To solve the serious problem of electron−hole pair recombination in perylene diimide (PDI) organic semiconductors, we loaded ferric hydroxyl oxide (FeOOH) on PDI materials, successfully prepared novel FeOOH@PDI photocatalytic materials, and constructed a photo-Fenton system. The system was able to achieve highly efficient degradation of BPA under visible light, with a degradation rate of 0.112 min−1 that was 20 times higher than the PDI system, and it also showed universal degradation performances for a variety of emerging organic pollutants and anti-interference ability. The mechanism research revealed that the FeOOH has the electron trapping property, which can capture the photogenerated electrons on the surface of PDI, effectively reducing the compounding rate of photogenerated carriers of PDI and accelerating the iron cycling and H2O2 activation on the surface of FeOOH at the same time. This work provides new insights and methods for solving the problem of easy recombination of carriers in semiconductor photocatalysts and degrading emerging organic pollutants.

Aiming to enhance the bandwidth in near-memory computing, this paper proposes a SSA-over-array (SSoA) architecture. By relocating the secondary sense amplifier (SSA) from dynamic random access memory (DRAM) to the logic die and repositioning the DRAM-to-logic stacking interface closer to the DRAM core, the SSoA overcomes the layout and area limitations of SSA and master DQ (MDQ), leading to improvements in DRAM data-width density and frequency, significantly enhancing bandwidth density. The quantitative evaluation results show a 70.18 times improvement in bandwidth per unit area over the baseline, with a maximum bandwidth of 168.296 Tbps/Gb. We believe the SSoA is poised to redefine near-memory computing development strategies.

Amidst the global energy and environmental crisis, the quest for efficient solar energy utilization intensifies. Perovskite solar cells, with efficiencies over 26% and cost-effective production, are at the forefront of research. Yet, their stability remains a barrier to industrial application. This study introduces innovative strategies to enhance the stability of inverted perovskite solar cells. By bulk and surface passivation, defect density is reduced, followed by a "passivation cleaning" using Apacl amino acid salt and isopropyl alcohol to refine film surface quality. Employing X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscopy (AFM), we confirmed that this process effectively neutralizes surface defects and curbs non-radiative recombination, achieving 22.6% efficiency for perovskite solar cells with the composition Cs0.15FA0.85PbI3. Crucially, the stability of treated cells in long-term tests has been markedly enhanced, laying groundwork for industrial viability.

This study investigates the carrier transport of heterojunction channel in oxide semiconductor thin-film transistor (TFT) using the elevated-metal metal-oxide (EMMO) architecture and indium−zinc oxide (InZnO). The heterojunction band diagram of InZnO bilayer was modified by the cation composition to form the two-dimensional electron gas (2DEG) at the interface quantum well, as verified using a metal−insulator−semiconductor (MIS) device. Although the 2DEG indeed contributes to a higher mobility than the monolayer channel, the competition and cooperation between the gate field and the built-in field strongly affect such mobility-boosting effect, originating from the carrier inelastic collision at the heterojunction interface and the gate field-induced suppression of quantum well. Benefited from the proper energy-band engineering, a high mobility of 84.3 cm2·V−1·s−1, a decent threshold voltage (Vth) of −6.5 V, and a steep subthreshold swing (SS) of 0.29 V/dec were obtained in InZnO-based heterojunction TFT.

In recent years, propelled by the rapid iterative advancements in digital imaging technology and the semiconductor industry, encompassing microelectronic design, manufacturing, packaging, and testing, time-of-flight (ToF)-based imaging systems for acquiring depth information have garnered considerable attention from both academia and industry. This technology has emerged as a focal point of research within the realm of 3D imaging. Owing to its relatively straightforward principles and exceptional performance, ToF technology finds extensive applications across various domains including human−computer interaction, autonomous driving, industrial inspection, medical and healthcare, augmented reality, smart homes, and 3D reconstruction, among others. Notably, the increasing maturity of ToF-based LiDAR systems is evident in current developments. This paper comprehensively reviews the fundamental principles of ToF technology and LiDAR systems, alongside recent research advancements. It elucidates the innovative aspects and technical challenges encountered in both transmitter (TX) and receiver (RX), providing detailed discussions on corresponding solutions. Furthermore, the paper explores prospective avenues for future research, offering valuable insights for subsequent investigations.

Here, p-type polysilicon films are fabricated by ex-situ doping method with ammonium tetraborate tetrahydrate (ATT) as the boron source, named ATT-pPoly. The effects of ATT on the properties of polysilicon films are comprehensively analyzed. The Raman spectra reveal that the ATT-pPoly film is composed of grain boundary and crystalline regions. The preferred orientation is the (111) direction. The grain size increases from 16−23 nm to 21−47 nm, by ~70% on average. Comparing with other reported films, Hall measurements reveal that the ATT-pPoly film has a higher carrier concentration (>1020 cm−3) and higher carrier mobility (>30 cm2/(V·s)). The superior properties of the ATT-pPoly film are attributed to the heavy doping and improved grain size. Heavy doping property is proved by the mean sheet resistance (Rsheet,m) and distribution profile. The Rsheet,m decreases by more than 30%, and it can be further decreased by 90% if the annealing temperature or duration is increased. The boron concentration of ATT-pPoly film annealed at 950 °C for 45 min is ~3 × 1020 cm−3, and the distribution is nearly the same, except near the surface. Besides, the standard deviation coefficient (σ) of Rsheet,m is less than 5.0%, which verifies the excellent uniformity of ATT-pPoly film.

The growth of high-quality germanium tin (Ge1–ySny) binary alloys on a Si substrate using chemical vapor deposition (CVD) techniques holds immense potential for advancing electronics and optoelectronics applications, including the development of efficient and low-cost mid-infrared detectors and light sources. However, achieving precise control over the Sn concentration and strain relaxation of the Ge1–ySny epilayer, which directly influence its optical and electrical properties, remain a significant challenge. In this research, the effect of strain relaxation on the growth rate of Ge1–ySny epilayers, with Sn concentration >11at.%, is investigated. It is successfully demonstrated that the growth rate slows down by ~55% due to strain relaxation after passing its critical thickness, which suggests a reduction in the incorporation of Ge into Ge1–ySny growing layers. Despite the increase in Sn concentration as a result of the decrease in the growth rate, it has been found that the Sn incorporation rate into Ge1–ySny growing layers has also decreased due to strain relaxation. Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge1–ySny epilayers with tuned Sn concentration and strain relaxation.

This paper presents the fabrication, characterization and numerical simulation of poly-3-hexylthiophene (P3HT)-based bottom-gate bottom-contact (BGBC) organic thin film transistors (OTFTs). The simulation is based on a drift diffusion charge transport model and density of defect states (DOS) for the traps in the band gap of the P3HT based channel. It combines two mobility models, a hopping mobility model and the Poole–Frenkel mobility model. It also describes the defect density of states (DOS) for both tail and deep states. The model takes into account all the operating regions of the OTFT and includes sub-threshold and above threshold characteristics of OTFTs. The model has been verified by comparing the numerically simulated results with the experimental results. This model is also used to simulate different structure in four configurations of OTFT e.g. bottom-gate bottom-contact (BGBC), bottom-gate top-contact (BGTC), top-gate bottom-contact (TGBC) and top-gate top-contact (TGTC) configurations of the OTFTs. We also present the compact modeling and model parameter extraction of the P3HT-based OTFTs. The extracted compact model has been further applied in a p-channel OTFT-based inverter and three stage ring oscillator circuit simulation.

Opening the silicon oxide mask of a capacitor in dynamic random access memory is a critical process on a capacitive coupled plasma (CCP) etch tool. Three steps, dielectric anti-reflective coating (DARC) etch back, silicon oxide etch and strip, are contained. To acquire good performance, such as low leakage current and high capacitance, for further fabricating capacitors, we should firstly optimize DARC etch back. We developed some experiments, focusing on etch time and chemistry, to evaluate the profile of a silicon oxide mask, DARC remain and critical dimension. The result shows that etch back time should be controlled in the range from 50 to 60 s, based on the current equipment and condition. It will make B/T ratio higher than 70% meanwhile resolve the DARC remain issue. We also found that CH2F2 flow should be ~15 sccm to avoid reversed CD trend and keep inline CD.

In this work, we achieve high count-rate single-photon output in single-mode (SM) optical fiber. Epitaxial and dilute InAs/GaAs quantum dots (QDs) are embedded in a GaAs/AlGaAs distributed Bragg reflector (DBR) with a micro-pillar cavity, so as to improve their light emission extraction in the vertical direction, thereby enhancing the optical SM fiber’s collection capability (numerical aperture: 0.13). By tuning the temperature precisely to make the quantum dot exciton emission resonant to the micro-pillar cavity mode (Q ~ 1800), we achieve a fiber-output single-photon count rate as high as 4.73 × 106 counts per second, with the second-order auto-correlation g2(0) remaining at 0.08.

In this work, a Cu2ZnSnS4 (CZTS) ingot is grown via a melting method, then cooled; the resulting molten stoichiometric mixture is sealed off in a quartz ampoule under vacuum. The CZTS powder chemical composition analyses are determined using energy dispersive spectroscopy, and revealing the slightly Cu-rich and Zn-poor character of the ingot. Powder X-ray diffraction analysis reveals a crystalline structure with a kesterite phase formation, and a preferred orientation of (112) plane. The lattice constants of the a- and c- axes, calculated based on the XRD analyses, are a = 5.40 Å and c = 10.84 Å. Based on Hall measurements at room temperature, we find that the crystal exhibits p-type conductivity, with a high concentration of 1018 cm–3, a resistivity of 1.7 Ω cm, and a mobility of 10.69 cm2V–1s–1. Activation energies are estimated based on an Arrhenius plot of conductivity versus 1/T, for a temperature range of 80–350 K, measuring 35 and 160 meV in low- and high-temperature regimes, respectively, which is attributed to complex defects (2CuZn+SnZn) and antisite defects (CuZn), respectively. The observed scattering mechanisms are attributed to ionized impurities and acoustic phonons at low and high temperatures, respectively. The extracted band-gap is 1.37 eV.

To clarify the contribution of oxygen vacancies to room-temperature ferromagnetism (RTFM) in cobalt doped TiO2 (Co-TiO2), and in order to obtain the high level of magnetization suitable for spintronic devices, in this work, Co-TiO2 nanoparticles are prepared via the sol–gel route, followed by vacuum annealing for different durations, and the influence of vacuum annealing duration on the structure and room-temperature magnetism of the compounds is examined. The results reveal that with an increase in annealing duration, the concentration of oxygen vacancies rises steadily, while the saturation magnetization (Ms) shows an initial gradual increase, followed by a sharp decline, and even disappearance. The maximum Ms is as high as 1.19 emu/g, which is promising with respect to the development of spintronic devices. Further analysis reveals that oxygen vacancies, modulated by annealing duration, play a critical role in tuning room-temperature magnetism. An appropriate concentration of oxygen vacancies is beneficial in terms of promoting RTFM in Co-TiO2. However, excessive oxygen vacancies will result in a negative impact on RTFM, due to antiferromagnetic superexchange interactions originating from nearest-neighbor Co2+ ions.

This paper presents the design and testing of a 15 Gbps non-return-to-zero (NRZ), 30 Gbps 4-level pulse amplitude modulation (PAM4) configurable laser diode driver (LDD) implemented in 0.15-µm GaAs E-mode pHEMT technology. The driver bandwidth is enhanced by utilizing cross-coupled neutralization capacitors across the output stage. The output transmission-line back-termination, which absorbs signal reflections from the imperfectly matched load, is performed passively with on-chip 50-Ω resistors. The proposed 30 Gbps PAM4 LDD is implemented by combining two 15 Gbps-NRZ LDDs, as the high and low amplification paths, to generate PAM4 output current signal with levels of 0, 40, 80, and 120 mA when driving 25-Ω lasers. The high and low amplification paths can be used separately or simultaneously as a 15 Gbps-NRZ LDD. The measurement results show clear output eye diagrams at speeds of up to 15 and 30 Gbps for the NRZ and PAM4 drivers, respectively. At a maximum output current of 120 mA, the driver consumes 1.228 W from a single supply voltage of –5.2 V. The proposed driver shows a high current driving capability with a better output power to power dissipation ratio, which makes it suitable for driving high current distributed feedback (DFB) lasers. The chip occupies a total area of 0.7 × 1.3 mm2.

Multifunctional lead-free double perovskites demonstrate remarkable potential towards applications in various fields. Herein, an environmentally-friendly, low-cost, high-throughput Cs2NaFeCl6 single crystal with exceedingly high thermal stability is designed and grown. It obtains a cubic lattice system in the temperature range of 80–500 K, accompanied by a completely reversible chromatic variation ranging from yellow to black. Importantly, the intriguing thermochromism is proved to own extremely high reproducibility (over 1000 cycles) without a hysteretic effect, originating from its structural flexibility that including (i) the noteworthy distortion/deformation of [NaCl6]5- and [FeCl6]3- octahedra; (ii) order–disorder arrangement transition of [NaCl6]5- and [FeCl6]3- octahedra as the function of temperature. This study paves the way towards a new class of smart windows and camouflage coatings with an unprecedented colour range based on a Cs2NaFeCl6 perovskite.

Here we demonstrate a room-temperature drop-coating method for MAPbI3 films. By using low-boiling-point solvent, high-quality MAPbI3 films were made by simply casting a drop of solution onto the substrate at room temperature. This approach took advantage of the synergistic effect of good wettability and volatility of the solvent, enabling high nuclei density and compact film at room temperature. The crystal growth in different solvents was in-situ observed by using optical microscope, which helped us to understand the mechanism for the formation of different film morphology. Perovskite solar cells gave a PCE of 18.21%.

The rapid rise in the power conversion efficiency (PCE) of CsPbBr2I-based perovskite solar cells (PSCs), from 4.7% in 2016 to 11.08% in 2020, render it a promising material for use in photovoltaic devices. However, the phase stability and current hysteresis caused by photo-induced phase segregation in CsPbBr2I represent major obstacles to further improvements in the PCE for such devices. In this review, we describe the basic structure and optical properties of CsPbBr2I, and systematically elaborate on the mechanism of the phase transition. We then discuss the strategies in progress to suppress phase transition in CsPbBr2I, and their potential application in the photovoltaic field. Finally, challenges and application prospects for CsPbBr2I PSCs are summarized in the final section of this article.

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