As one kind of semiconductor material with the superiorperformance, single crystal diamond (SCD) has broad application prospects in power devices, deep space exploration and other fields. However, SCD prepared viamicrowave plasma chemical vapor deposition (MPCVD) usually contains defects, especially dislocations, seriously restrictingits electrical performance. Lateral epitaxial growth as a common defect control method in semiconductor materialsis used in SCD preparation in recent years. In this work, firstly,a pattern array was constructed on SCD seed by metal catalyzed plasma etching to create a lateral growth condition for the preparation of homogeneous epitaxial. Secondly, SCD layer was prepared by MPCVD method, and the lateral epitaxial growth process was investigated. The samples were tested by laser confocal microscopy, polarizing microscopy, Raman spectroscopyand defect density measurement. The results show that this method can stably and controllably prepare the arrays needed for patterned growth and reduce the defect density of the growth layer.

The application of CaF2 crystal in photolithographic machine becomes a hot research topic. However, differentdefects in the crystal seriously restrict its actual performance. In this paper, the morphological and spatial extension characteristics of etch pits formed by the crystal face (111) of CaF2 crystal were observed, and the corresponding defect characteristics of various etch pits were analyzed, which is aprerequisite for the accurate characterization and control of crystal defects. The results show that the etch pits on the crystal face (111) of CaF2 have three types, i.e.,triangular conical pit, cone-flat bottom pit and flat bottom pit. Triangular conical pits and cone-flat bottom pits have directional movement characteristics, indicating that the corresponding defects of these pits are related to the dislocations of the materials. However, there is no spatial extension in the flat bottom pit, which is formed after the defects are completely corroded, and the corresponding defects may be the remains of local defects such as impurities, vacancies and small dislocation rings. The physical parameters of the formation process of the etch pit are obtained, and the kinematic model of the etch pit is establishedby tracking the evolution process of the etch pit in real time. This work provides a basis for further studiesonthe corrosion theory of crystal materials.

In recent years, low dimensional organic-inorganic hybrid copper(I) halides have a great potential in the fields of photoelectric and radiation detection applications due to their high fluorescence quantum efficiency, excellent stability, and low-cost processing feasibility. We prepared a zero dimensional (0D) (TPA)CuI2 (TPA=tetrapropylammonium, C12H28N+) single crystal scintillator by a simple solution evaporation method, and investigate its optical and scintillation properties. (TPA)CuI2 crystal has a high thermal stability and an air stability. Under UV excitation, it exhibits an ultra-broadband white light emission with a full width at half-maximum (FWHM) of 291 nm and a photoluminescence quantum yield (PLQY) of 62%. Under X-ray excitation, it has an intense radioluminescence, a low afterglow and a decent detection limit, which can be regarded as a novel X-ray scintillator.

Yttrium aluminium garnet (YAG) crystals have applications in optoelectronics, and the defect control of crystal growth is a bottleneck problem to be solved. In this work, the dislocation etch pit morphology and density distribution were investigated in YAG crystal grown by the Czochralski method with and without necking technology, and the YAG crystal samples were polished and etched with phosphoric acid. The dislocation etch pits were photographed by a metalphase microscope. The results show that the dislocation density of YAG crystal is the maximum in the initial shoulder part and the minimum in the cylinder part, as well as a little greater at the end part. The dislocation density in necking end is reduced. In addition, the YAG dislocation etch pit of different crystal directions was analyzed, and the surface energy of each YAG crystal surface was calculated, indicating that the relatively stable plane of YAG etch pit is (110) and (112). Based on the analysis by the stereographic projection, the lattice plane stability of (110) and (112) and their position relation to other lattice planes are the important reasons for the formation of etch pit morphology.

β-Ga2O3 is one of the most promising ultrawide band-gap semiconductor materials, but its crystal defects are not investigated comprehensively. The low angle grain boundaries of β-Ga2O3 crystal mainly exists in (100) plane. The existence of low angle boundary can destroy the integrity of the crystal structure and reduce the quality of crystal. The macroscopic analysis and microstructure characterization of the low angle grain boundaries in the β-Ga2O3 crystal grown by edge-defined film-fed growth method were carried out by chemical etching analysis and transmission electron microscopy. The results show that the shape and orientation of the etch pits on both sides of the low angle grain boundary are consistent, and the misorientation angle of the low angle grain boundary is 3°. In addition, the low angle grain boundary can cause the double peaks and broadening in the X-ray rocking curve. The gap in the study of low angle grain boundary is filled based on the characterization of the microstructure of low angle grain boundary in β-Ga2O3 crystals.

KDP crystal is a nonlinear optical material that is used in inertial confinement nuclear fusion devices. However, the defects seriously reduce the optical performance such as light absorption and laser damage threshold of KDP crystals. It is thus of great significance to investigate the influence mechanism of KDP crystal defects on its electronic structure and optical properties for the improvement of its optical properties. In this paper, the structure, stability and electronic structure of hydrogen and oxygen vacancy defects (i.e., VH and VO) on the growth surfaces (100) and (101) of KDP crystals were investigated by using the first-principle calculation. The effect and microscopic mechanism of acidic environment on the structure and properties of surface defects were also discussed. The results indicate that the VH and VO defects both are easier to be formed on the surfaces (100) and (101) rather than in bulk KDP crystal. The surface (100) has an intense tolerance for surface VH and VO defects, while VO on the surface (101) prefers to lose electrons, and introduces a deep defect level in the band gap, thusdamagingthe optical properties of the KDP crystal. In addition, acidic environment canlead to more VO defects on the surface (100) and introduce the defect level in the band gap. Also, acidic environment is conducive to the repair of the VH defects on the surfaces, and can eliminate the defect states introduced by the surface VO defects on the surface (101), which is conducive to improving the quality and optical quality of the crystal surfaces.

There are abundant defect structures in lithium niobate crystals, mainly including VLi, NbLi4+, VNb and VO point defects. The existence of defects greatly affects the properties of lithium niobate crystal(i.e., piezoelectric, electro-optic, ferroelectric, photorefractive, nonlinear optical properties and laser damage threshold) as well as the performance of SAW, electro-optic modulator, acousto-optic modulator, temperature/pressure/acceleration sensor and other devices. The main process of defect formation in lithium niobate crystal can be attributed to the evolution of mesoscale clusters centered on O2?傆b ions. It is thusimportant to understand the evolution mechanism of mesoscale clusters in the defect formation process of lithium niobate crystal for defect control. This paper was to investigate the dynamic evolution process and formation mechanism of defects in lithium niobate crystal from the aspects of defect types, formation energy and mesoscale cluster model. The hybridization and rehybridization process caused by defects in lithium niobate crystal structure was analyzed, and the coupling of multiple degrees of freedom was considered, which contributes to the defect control, rapid growth and performance control of lithium niobate crystal. In addition, the correlation between the defects of lithium niobate crystal and its properties as well asfunctions was also analyzed

Aluminum nitride (AlN) is a direct bandgap semiconductor with a ultrawide bandgap width (i.e., 6.2 eV), a high thermal conductivity (i.e., 3.4 W/(cm·K)), a high surface acoustic rate (i.e., VL=10.97×105 cm/s, VT=6.2×105 cm/s), a high breakdown field strength as well as stable physical and chemical properties. AIN is an ideal substrate for ultraviolet/deep ultraviolet (DUV) luminescent materials. AlxGa1-xN materials made from AlN can achieve a continuous luminescence in a wavelength range of 200-365 nm. AlN crystal as one of developed semiconductor materials with a great potential can be used for high voltage, high temperature and high frequency electronic devices. This review introduced the heteroepitaxial growth principle of AlN single crystal by a physical vapor transport (PVT) method. Recent research progress on the heteroepitaxial growth of AlN on silicon carbide (SiC) substrate was represented based on the corresponding studies on the AlN growth on SiC substrates and the growth of AlN crystals on AlN/SiC substrates and off-orientation SiC substrates. Some challenges and opportunities of growing AlN single crystal on SiC substrate were briefly described, and the future development of AlN materials was prospected as well.

Garnet-based phosphor materials have some advantages of multi-site of doping icons, a wide option of doping ions, and a high efficiency of energy transfer, thus becoming a research hotspot for inorganic luminous materials. Compared with rare-earth ions, transition metal ions have superior features of spectral regulation and low cost. However, its luminous efficiency, valence, and luminous mechanism in complex lattice structures are still unclear. This review summarized the spectral characteristics and luminescent behavior of transition metal ions, especially Cr3+, Mn2+/4+. In addition, the application of transition metal ions in the fields of solid-state lighting, displays, biomedical imaging, and plant lighting was also represented.

With the rapidly development of 5G and 6G technologies, developing ceramics with a moderate dielectric constant, a high quality factor, and a resonant frequency temperature coefficient close to 0 becomes a research hotspot. A novel series of microwave dielectric ceramics Ca0.95?偉dxCu0.05(Na0.5Bi0.5)xMoO4 were synthesized by a solid-state reaction method. The influences of sintering temperature and component change on the microwave dielectric properties were investigated. The ceramic property was analyzed by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results show that the εr of Ca0.45Cu0.05(Na0.5Bi0.5)0.5MoO4 ceramic with NB content of 0.5 sintered at 640 ℃ is 15.8, Qf is 21 361 GHz, and τf is 3.8×10-6/℃. Also, Ca0.45Cu0.05(Na0.5Bi0.5)0.5MoO4 ceramic is compatible with Al electrode, indicating that Ca0.95-xCu0.05(Na0.5Bi0.5)xMoO4 ceramic has a great potential application as a low-temperature co-fired ceramic material.

The optimization of dielectric properties for high dielectric perovskite-like ceramics is a research hotspot. (NaLn)Cu3Ti4O12 (Ln=Ce; Nd) dielectric ceramicswere prepared by ahigh-temperature solid-state methodat different sintering temperatures. The phase characteristics, microstructure and dielectric properties of the dielectric ceramics were investigated. The results show that (NaLn)Cu3Ti4O12 (Ln=Ce; Nd) ceramics are single-phase ceramics. The dielectric constant of (NaLn)Cu3Ti4O12 ceramics increasesand the dielectric loss changeswith the increase of sintering temperature. Different doping ions caninduce the corresponding polarization mechanism, further causingdifferent dielectric properties. (Na1/3Ce2/3)Cu3Ti4O12 ceramics prepared at 1 000 ℃ havethe higher dielectric properties, i.e., ε=50 552 at 10 Hz. However, the dielectric loss of (Na1/2Nd1/2)Cu3Ti4O12 ceramics prepared at 950 ℃ is smaller, i.e., tanδ=0.09 at 10 Hz.

Pb0.9625Sm0.025［(Mg1/3Nb2/3)0.71Ti0.29］O3 ceramic material with a high piezoelectricity wasprepared by a two-step oxide solid reaction method. The effects of driving field amplitude and temperature on the radial resonance characteristics were investigatedby a large signal resonant response test system. The results show that the resonant response at a low driving field can maintain a single resonant peak until complete depolarization. However, the resonant response becomes complicated, and some multiple resonant peaks appear even at a low temperatureas a driving field increases. The resonant properties areclosely related to the mechanical quality factor Qm, ferroelectric domain size and phase composition. The thermal effect produced by applying a high driving field on the low Qm material accelerates the splitting of macro-domains and induces a first-order ferroelectric phase transition. The instability of resonant characteristics and the large resonant frequency temperature coefficient restrictthe application of Sm-doped PMN-PTrelaxor ferroelectric ceramics, especially at a high driving field.

Three silicon nitride ceramic balls were prepared via hot static pressing (HIP). In addition to some conventional sintering aids like Al2O3 and Y2O3, TiN, Fe3Si and WC transition metal compounds were incorporated into the powder mixtures before ball-milling and HIP, respectively. The microstructures and mechanical properties of the silicon nitride ceramic balls prepared were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nano indentation (NI) analysis. The results indicate that TiN additive has an effect of suppressing the formation of Si2N2O during sintering. TiN and WC additives can promote the diffusion of Al and O into silicon nitride matrix during sintering, resulting in the formation of some sialon phase. However, Fe3Si additive has little effect as mentioned above. TiN additive has an effect of refining the microstructure, thus obtaining a refined grain structure with an even size distribution. Fe3Si additive tends to produce a microstructure of long-coarse-grain intersected and bridged frame filled by grains. WC additive leads to the development of an uneven microstructure containing the coarser and finer grains. Compared to the balls containing Fe3Si or WC additives, the ball containing TiN additive has better mechanical properties, i.e., higher hardness and greater modulus of elasticity.

Ca2Mg2Al28O46 (C2M2A14) refractory has a superior high-temperature performance for high-temperature kilns. In this paper, a ternary compounds-C2M2A14 was synthesized via high-temperature solid-state reaction sintering. Effects of firing temperature and Fe2O3 addition on the phase composition, fabric and densification evolution of the specimens were investigated. The results show that the C2M2A14 is generated by the reaction of CaAl12O19 (CA6) with spinel at 1 650 ℃, and is produced in large quantities at 1 750 ℃. The densification evolution is accelerated with the transformation from hexagonal lamellar CA6 to polyhedron C2M2A14 and the appearance of eutectic liquid. The hexagonal plate of (1,1,15) preferred orientation is changed to the rhombohedral of (119) preferred orientation after adding Fe2O3, and the densification evolution is promoted, and more dense synthetic products can be obtained at the same firing temperature due to the solid solution strengthening of Fe ions. The apparent porosity, water absorption, and bulk density of C2M2A14 (1% Fe2O3) specimen fired at 1 780 ℃ for 3 h are 12.5%, 3.9%, and 3.20 g瘙
簚cm-3, respectively. A high-temperature refractory is obtained.

The electrolyte of the proton conducting solid oxide fuel cell is the key component affecting both the performance and the stability. In this study, B-site cation-doped BaCe0.9M0.1O3-δ (BCM, M=Sc, Y, Zr, Nb) proton conducting ceramics are prepared via solid-state reaction approach. The effect of B-site doping on its sintering characteristics and mechanical properties are examined by material characterization and nanoindentation test. The results show that trivalent ion doping can promote the particle growth during sintering, while high-valent ion doping can inhibit the particle growth. In terms of mechanical properties, the Young’s modulus of the doped BCM decreases with the increase of the ionic radius of the trivalent doping elements (Sc and Y), and decreases with the increase of the valence state of the different valent doping elements (Y, Zr, and Nb).

BaTiO3-Bi(Mg0.5Zr0.25Ti0.25)O3 ceramic was prepared by a solid-state method, and the influence of Bi(Mg0.5Zr0.25Ti0.25)O3 content on the microstructure, dielectric, ferroelectric and energy storage properties of BaTiO3-based ceramics was investigated. The ceramic has a tetragonal phase structure when the sample composition x≤0.03, and the structure of the ceramic changes from a tetragonal phase to a cubic phase when x≥0.06. This ceramic shows a good temperature stability. The dielectric constant peak becomes wider and lower, and the material gradually changes from a ferroelectric to a relaxor ferroelectric as Bi(Mg0.5Zr0.25Ti0.25)O3 content in the composition increases. The dielectric constant of the sample keeps stable from room temperature to 500 ℃. The addition of Bi(Mg0.5Zr0.25Ti0.25)O3 can make the hysteresis loop to be slimer, the remnant polarization Pr decreases, and the integral area of the upper branch of P-E loop with respect to the polarization axis become larger. Thus, the material energy storage density increases. The energy storage density of the material firstly increases and then decreases, while the energy storage efficiency increases from 75.08% to 92.35%. The maximum energy density of 0.80 J/cm3 can be obtained with a high efficiency of 88.97% as x=0.1.

Sodium niobate(NaNbO3)-based lead-free ceramics have attracted much attention in the pulse power capacitors due to their non-toxicity and superior energy storage properties. However, the large recoverable energy-storage density (Wrec) and efficiency (η) cannot be achieved simultaneously, thus restricting their commercialization. This work proposed astrategy of increasing the relaxation characteristics to improve the energy storage performance via constructing a local random field. The (1-x)(0.96NaNbO3- 0.04CaZrO3)-xBi0.5Na0.5TiO3 (x=0.05, 0.10, 0.15, and 0.20) antiferroelectric energy storage ceramics were prepared by a conventional solid-state method. The effect of Bi0.5Na0.5TiO3 content on the phase structure, microstructure and dielectric, ferroelectric as well as energy storage properties of 0.96NaNbO3-0.04CaZrO3 ceramics was investigated. The results show that the microstructure of each ceramic is homogeneous and dense. The (1-x)(0.96NaNbO3-0.04CaZrO3)-xBi0.5Na0.5TiO3 solid solution transformsfrom antiferroelectric orthorhombic P phase (x≤0.10) to antiferroelectric orthorhombic R phase (x≥0.15), accompanied by abroadening dielectric peak moving towards the lower temperatures as Bi0.5Na0.5TiO3 content increases, thus having the representative relaxation characteristics. The 0.85(0.96NaNbO3-0.04CaZrO3)-0.15Bi0.5Na0.5TiO3 ceramic has a maximum energy storage density Wrec of 1.614 J/cm3 and a high energy storage efficiency η of 83.97% under 260 kV/cm at room temperature. Besides, the ceramic exhibits a good temperature stability at 25-150 ℃ (the variation of Wrec less than 15%) and a high energy storage efficiency, which can be used as a promising material for high-temperature pulsed power capacitors.

Allochroic effect of rare-earth molybdate materials is related to the reflection spectrum and the power distribution of illuminants. Based on the chromaticity, the power distribution of four standard illuminants (i.e., D65, A, F2 and F11) were compared for constructing the illuminant difference functions (IDF), indicating that a significant allochroic effect of the materials usually occurs between two illuminants with a great difference in the power distributions. The allochroic effect appears when the minimum reflectivity is near asharp peak of IDF, while the color difference is small asthe minimum reflectivity isfar away from the sharp peak. Rare-earth ions with a potential allochroic effect were selected based on the atomic characteristic absorption spectra, and rare-earth molybdate materials synthesized via solid-state reaction were used for the related experimental validation.

A demand for large size and high-performance potassium dideuterium phosphate crystals (DKDP) is increasing with the development of high-power laser system. Compared with the conventional methods, a rapid growth method can shorten the crystal growth period and improve the crystal growth efficiency. However, the properties of the rapidly growing DKDP crystals in pyramidal and prismatic regions are different, leading to the inhomogeneity of the properties in different positions and restricts its application in high-power laser systems. In this paper, potassium dideuterium phosphate crystals with a medium size were grown by a point seed rapid growth method. The feasibility of using rapidly-growth DKDP crystal as electro-optical switch and frequency converter was analyzed by transmittance spectroscopy according to the linear absorption properties. The homogeneity of deuterium content and the crystal quality were analyzed by Raman spectroscopy and rocking curve analysis, respectively. This work can provide a reference for the growth and application of large size potassium dideuterium phosphate crystal.

Y3Al5O12-Al4SiC4 composite refractory was prepared via pressureless sintering with Al4SiC4 as a raw material and Y2O3 as an additive. The effect of Y2O3 addition (i.e., 0-5% in mass fraction) on the phase composition, microstructure and mechanical properties of the composite was investigated, and the effect of Y3+ ions on the surface energy of Al4SiC4 different crystal faces was calculated via the DFT simulation. The results show that the addition of Y2O3 can form an eutectic liquid phase with anintrinsic oxide layer on the surface of Al4SiC4 at a high temperature, Y3Al5O12 and a small amount of Y2SiO5 appear at the grain boundary of the composite.The addition of Y2O3 promotes the growth of Al4SiC4 grains along the two-dimensional plane and the transformation from irregular to hexagonal flakes due to the reduction of surface energy of different crystal faces of Al4SiC4 by Y3+ in the additive, according to the DFT results. The flexural strength of the composite first increases and then decreases with the increase of Y2O3 addition. At theY2O3 addition of 3%, the hexagonal lamellar Al4SiC4 grains with a uniform size form a staggered skeleton structure, and Y3Al5O12 dispersesat the grain boundary of Al4SiC4, which is conducive to the improvement of the mechanical properties of Y3Al5O12-Al4SiC4 composite. The bulk density, apparent porosity and flexural strength of the composite are 2.44 g·cm-3, 20.15% and 52.7 MPa, respectively.

The thermal shock resistance of mullite castable with different steel fiber contents (i.e., 0-2.5% (mass fraction)) was evaluated by a wedge splitting method and a thermal stress factor. The thermal shock resistance of the castable was also analyzed by three different thermal shock resistance characterization methods (i.e., the residual ratio of modulus of rupture, modulus of elasticity and ultrasonic wave velocity in air at 1 100 ℃. The results show that the fracture energy (R'''') and fracture toughness increase with the increase of steel fiber content from 1.0% to 2.0%, thus improving the thermal shock resistance of castable. The rapid generation and propagation of cracks can lead to a decrease of R'''' and thermal shock resistance when the addition of steel fiber exceeds 2.0%.

Activity is a main application characteristic that is closely related to the microstructure of light-burned magnesia. The light-burned magnesia was obtained via calcining macrocrystalline magnesite powder at 700-1 100 ℃. The cell parameter, grain size, crystallinity, specific surface area, pore diameter distribution, specific pore volume, average pore diameter, activity and microstructure of light-burned magnesia at different temperatures were characterized. The particulate structure of light-burned magnesia was investigated by thermogravimetry based on the non-isothermal reaction kinetics theory, and the mechanism of the particulate structure evolution with temperature and its influence on the activity of light-burned magnesia were further analyzed. The results show that the cell parameter a0 of light-burned magnesia firstly reduces and then becomes stable, and the grain size increases while the specific surface area decreases gradually when the calcination temperature increases from 700 ℃ to 1 100 ℃. However, the activity of light-burned magnesia does not comply with this rule, and reaches the maximum value at 800 ℃. The thermal decomposition of macrocrystalline magnesite powder is controlled via the chemical reaction at the phase interface. The decomposition product, i.e., the light-burned magnesia ‘pseudo’ particles, is composed of magnesia microcrystals and connected a pore network structure. The sintering of magnesia microcrystals affect the "pseudo" particle structure of light-burned magnesia as the calcination temperature increases, thus affectingits activity. The sample light-burned at 800 ℃ has a smaller grain size, a lower crystallinity, a larger specific pore volume, and a largest average pore size due to the lattice adjustment, which is conducive to the penetration of the reactant solution into the particles and accelerates the reaction progression, leading to the maximum activity.

Ceramic cores have an impact on the precious casting of the engine hollow blades. 3D printing technology, as a novel generation of molding technology, is replacing the conventional ceramic core manufacture process due to the advantages of no mold, short manufacturing cycle, and high accuracy. This review summarized the existing 3D printing technologies for ceramic cores such as light-curing technology, selective laser sintering, direct-write forming technology and layered extrusion, and discussed the current research work on the performance optimization for ceramic cores prepared by 3D printing based on their shortcomings (i.e., low printing accuracy, poor compatibility between mechanical property and porosity, and anisotropy in structure and property). In addition, the future development of this technology was also prospected.

Polymer derived Al-containing silicon carbide (SiC) ceramic fibers as one of the ideal reinforcers for high-temperature ceramic matrix compositeshavesuperiorproperties such as high tensile strength, high modulus, high temperature and oxidation resistance. This review represented development on thepreparation of polymer derived Al-containing SiC ceramic fibers (i.e, synthesis and mechanism of polyaluminocarsilane (PACS), curing method of PACS fibers and controlling defects of Si(Al)C fibers). The advantages and disadvantages of existing PACS synthesis routes and curing processes of PACS fibers were discussed. In addition, this review alsoprospected the future sustainable aspectsto develop new PACS synthesis route and efficient curing method for improving the mechanical properties of Si(Al)C ceramic fibers.

The limited lithium resources and the great risk of conventional liquid-state electrolyte can affect the development of all-solid-state sodium-ion batteries. As a core component of all-solid-state sodium battery, sodium-ion solid-state electrolyte can play an important role in improving the safety and electrochemical performance of the battery. NASICON-type solid-state electrolyte Na1+xZr2SixP3-xO12(0≤x≤3) is widely concerned due to its unique 3D open structure and good chemical/thermal stability. This review represented recent research work on the crystal structure, ion transport mechanism, powder preparation methods and sintering methods of Na1+xZr2SixP3-xO12. Two major issues of Na1+xZr2SixP3-xO12 were discussed, i.e., a low ionic conductivity and a poor contact issue at the electrode-electrolyte interface, and the relevant modification methods were summarized. In addition, the optimization scheme of Na1+xZr2SixP3-xO12 and the possible development trend in the future were prospected. This review could play a guiding role in the future research of NASICON solid-state electrolyte and solid-state sodium battery.

Phosphorus-based anode materials have a high theoretical capacity and a medium redox potential, and the related raw materials have some advantages in reserves and costs, thus having promising application prospects in sodium and lithium-ion battery anode materials. However, red phosphorus has a fast decay rate of electrochemical activity and a poor cycling performance due to the extremely low electronic conductivity and excessive volume expansion, while black phosphorus conductivity can reach 105 S/m, and its dense structure leads to a poor intrinsic rate performance, thus restricting the practical application of elemental phosphorus as an anode material. A unique metal phosphorus-rich phosphides MPx (x≥2) can be formed by introducing a small amount of metal elements into elemental phosphorus. The electronic conductivity of metal phosphorus-rich phosphides MPx can be greatly improved via metal element electron injection, and a relatively empty crystal structure can be formed to provide faster reaction kinetics and effectively inhibit volume expansion. Therefore, metal phosphorus-rich phosphides MPx with a high capacity and superior electron/ion transport characteristics is a potential sodium and lithium-ion battery anode material. This review mainly represented the composition and structural characteristics of metal phosphorus-rich phosphides, focusing on the latest progress in the energy storage mechanism and modification strategy of metal phosphorus-rich phosphides.

Density functional theory (DFT) is a quantum mechanical method for electronic structure calculations, which becomes an effectivecomputational tool in materials science and chemistry. In the study of fluorescent materials, DFT calculations can be used to determine the crystal structure, calculate the materials band structure, and density of states information to clarify the nature and characteristics of fluorescent materials, thus providing a basis for material design and optimization. In addition, high-throughput computations based on DFT calculations can rapidly evaluate the properties of numerous materials, accelerate the development process of new materials, and reduce research costs. This review introducedthe application of DFT calculations in the study of fluorescent materials and discussed the future development prospects.