Optoelectronic Technology
Co-Editors-in-Chief
Xiangzhen Chen
Ting LIU, Zeyang WANG, Shu HU, Yang ZHANG, Heng LI, and Chuanxiang SHENG

The structure of two-dimensional perovskites and their corresponding unique exciton properties were introduced, especially the characteristics of phonon in the spectrum. It was analyzed that the strong electron?phonon interaction may be the physical reason why n=3-based mixed two-dimensional perovskites were suitable for photoelectric materials. Finally, the further problems were clarified in order to provide ideas for the optimization of two-dimensional perovskite optoelectronic materials and devices.

Jan. 12, 2021
  • Vol. 40 Issue 4 229 (2020)
  • Wenfeng GAN, Xiren ZHANG, Hong ZHANG, and Yan LI

    The application history and research progress in machine-learning-based optical controlling and imaging through scattering media were reviewed,and several representative machine learning algorithms and network architectures were analyzed in detail. Finally, the research progress and trend of the machine learning used in optical controlling and imaging through scattering media were summarized. Existing problems and future research priorities were discussed as well.

    Jan. 12, 2021
  • Vol. 40 Issue 4 239 (2020)
  • Guobing ZHENG, Yunchang CHEN, Lei SUN, Lu WANG, Xumeng QIU, Zhaobang FU, and Yijie ZOU

    The different kinds of LOCA(liquid optical clear adhesive) between organic silicon and acrylic adhesive were compared, and the influence of different performance parameters on bonding process and quality were introduced. The solutions were proposed for the questions, such as degumming、bubbles、MURA in LOCA’s application,providing forceful technical support for the widely application of adhesive.

    Jan. 12, 2021
  • Vol. 40 Issue 4 251 (2020)
  • Jiwei ZHU, Ji YANG, Xueqiang GUO, Shulong FENG, Tingting MA, Hanzhou GUO, and Chunyang SHEN

    Based on high-speed FPGA technology, the driving research of collecting spectral signal was realized by using line array CCD controlled by external trigger synchronization according to external demand. According to the test data in this paper, it could be seen that the fixed delay time of the designed circuit board was 2.809 9 μs, and the delay accuracy was no more than 86.1 ns, and the spectral signal collected by the linear array CCD could meet the requirements of spectral analysis. This paper designs and realizes the optical signals collected by the external trigger mode to control the TCD1304, providing application reference for later industrial testing.

    Jan. 12, 2021
  • Vol. 40 Issue 4 265 (2020)
  • Xiaoxuan DONG, Minggang LIU, Xiangang LUO, and Ping GAO

    In order to realize the gap measurement between the mask and the substrate in the surface plasma lithography machine, a gap measurement method of the mask-substrate gap was proposed based on white light interferometry, and a signal processing system was designed based on ZYNQ. ZYNQ''s on-chip ARM was used for parameter setting, drive control, and front-end display. The programmable logic resources were used to realize wavelet processing and cross-correlation demodulation of spectral data. This system operated in a distributed parallel structure, which could greatly improve the detection speed, and realize the real-time measurement of the mask-substrate gap. Finally, in order to determine the measurement accuracy, a laser interferometer accuracy test platform were built. Test experiments showed that the repeat measurement accuracy was 4.4 nm, and the displacement measurement accuracy was 6.7 nm. It could satisfy the gap measurement system requirements of stabilization and higher precision.

    Jan. 12, 2021
  • Vol. 40 Issue 4 277 (2020)
  • Jiashun TAO, and Xiang LIU

    The performance and stability improvement of back channel etched indium-gallium-zinc oxide thin-film transistors (IGZO TFTs) by optimized passivation layer was investigated. It was revealed that the positive threshold voltage (Vth) shift occurred under the positive gate bias stress (PBS). Analysis showed that the permeated moisture could degrade TFT performance and aggravate the positive Vth shift under PBS. It was demonstrated that the optimized passivation layer could effectively improve the device performance and Vth stability. This improvement is attributed to lessen the traps caused by absorbance on back channel surface.

    Jan. 12, 2021
  • Vol. 40 Issue 4 298 (2020)
  • Ying GAO, and Xingyu ZHOU

    Top-gate self-aligned a-IGZO TFT is suitable for driving OLED displays for its tiny parasitic capacitors. In order to improve the stability of TFT device under illumination condition, the driving TFT usually needs light shading layer. In this paper, the influence of the light shading layer, the selection of its signal connection, the thickness of the buffer layer and the size of the light shading layer were explored. The results showed that: (1) the light shading layer could effectively reduce the negative bias caused by the light of TFT, (2) the light shading layer connecting signal was more stable than the floating one, and the TFT whose shading layer was connected to the source electrode was more easily saturated, which could be helpful to carry out OLED, (3) buffer layer thickness of 400 μm was more favorable for device performance, (4) the light shading layer should cover IGZO, and its size should be as large as possible, which could effectively improve the device reliability.

    Jan. 12, 2021
  • Vol. 40 Issue 4 302 (2020)
  • Long SHEN, Guochao QIAN, Fangrong ZHOU, Zhaoyu PENG, Yutang MA, Weiju DAI, and Changjie XIA

    A novel SiPM sensor system suitable for internal PD detection in GIS was designed, which had obvious advantages such as low drive voltage, small volume and high photon conversion rate. The consistency of the new SiPM sensor system, photomultiplier tube (PMT) and high frequency current transformer (HFCT) of pulse current detection device for PD detection was verified through the PD light-electric joint test, and the validity of phase resolved partial discharge method on SiPM detection results was also proved. On this basis, the field installation mode of SiPM was studied and tested. The results showed that the SiPM sensor system could achieve excellent detection effect in the field application and provide technical support for the field application of optical measurement method.

    Dec. 30, 2020
  • Vol. 40 Issue 4 258 (2020)
  • Yuanpeng FAN, Haoran MENG, Xinyue LIU, Xinran LIU, and Yue WANG

    A dynamic digital holographic imaging system using a polarization camera integrated with a micro-polarizer phase shift array to achieve parallel phase shift was designed and implemented. The system used a quarter wave plate to turn the reference light and the measurement light into circularly polarized light with opposite rotation, then used the micro-polarizer phase shift array on the polarization camera to obtain four holograms with phase shift difference of π/2, and then used the four step phase shift algorithm to demodulate the measurement light field distribution of the hologram, and finally used the angle spectrum method to reproduce the image in the near field. The simulation and experimental results show that the technique successfully eliminates the interference of zero-order and twin images, and can record the dynamic changes of the objects to be measured in real time, and quickly obtain the reproduced image with micron resolution.

    Dec. 30, 2020
  • Vol. 40 Issue 4 270 (2020)
  • Bing XU, Yuefei CHEN, Chang ZHOU, Jianhua ZHANG, and Xifeng LI

    A template matching method based on SNCC(self-normalized cross correlation)was proposed, which was based on the invariance of center rotation of centro-symmetric markers. This method had strong process adaptability to the non-linear scaling deformation caused by TFT process and the defocusing of markers. Through the contrast test of alignment mark and defocus alignment mark of TFT process deformation, it was verified that under this condition, the measurement results based on SNCC method had higher reliability than NCC (normalized cross correlation) and geometric template matching algorithm, and could meet the needs of accurate positioning and measurement at sub-pixel level of centrosymmetric marker. Compared with the traditional mark center positioning method, the proposed method could still obtain high reliability measurement results when the alignment mark produced process deformation or alignment defocusing.

    Dec. 30, 2020
  • Vol. 40 Issue 4 284 (2020)
  • Ye YUAN, Qibin FENG, and Guoqiang LYU

    Holographic waveguide could effectively decrease the weight and volume of a near-eye display system. As an important component, incouple/outcouple grating could heavily affect the final display brightness. The diffractive efficiency of a three-step grating with random duty cycle was firstly calculated and it was found that the grating with the same step width presented the highest diffractive efficiency. The simulations based on rigorous couple wave theory were exploited to analyze how grating height could affect diffractive efficiency in the case of different refractive indexes. The simulation results showed that when the refractive efficiency of the grating was 1.52 and 1.74, the grating height should be 700 nm and 470 nm to guarantee the highest diffractive efficiency. When the grating height was 100 nm less than the designed height, the diffractive efficiency decreased from 60% to 56% and from 59% to 47%, respectively. The designed grating was prepared by maskless direct-writing lithography. The measured -1 order diffractive efficiency could reach 49.7% and the output image could be clearly displayed at the end of the waveguide. The proposed three-step grating presents the merits of short preparation duty, low cost and high efficiency.

    Dec. 30, 2020
  • Vol. 40 Issue 4 291 (2020)
  • Mudi XIONG, Yujun GUO, Jin LI, and Kun ZHANG

    A new type of LED smart glass display driver was proposed. This driver was based on the principle of pulse width modulation. The special driver chip in the driver converted the input serial video data into multi-channel parallel grayscale control data, and then drove the LED smart glass display through the FPC soft board to realize the full cycle of each frame of data and 4 096 levels of grayscale multi-level display. Multiple drivers could be cascaded, so that multiple LED smart glass displays could be cascaded to increase the display screen. At the same time, the driver also could have the advantages of light weight, moderate volume and price. Each pixel of the screen has bright colors and stable display, and could be widely used in indoor and outdoor LED smart glass display.

    Dec. 30, 2020
  • Vol. 40 Issue 4 295 (2020)
  • Jiadi YAO, Yulong HOU, Yucong PAN, Yiming SU, and Shuiwang YANG

    A quasi-distributed liquid leakage sensing device were introduced, which used POF optical fiber and LED light belt to realize the detection of multi-source optical fiber scanning positioning. The use of SM16703P was mainly introduced to design LED light belt power supply and control circuit, in order to achieve low cost, high real-time leakage detection and leakage location.

    Dec. 30, 2020
  • Vol. 40 Issue 4 308 (2020)
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