Sponsor:Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Luminescence Branch of Chinese Physical Society, State Key Laboratory of Luminescence and Applications
Publication frequency:Monthly
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GAO Mengdi, CAO Qing, SONG Shiyu, LIU Kaikai, SHAN Chongxin
DOI:10.37188/CJL.20240344
摘要:The emission of ZnO in the visible light region has a long and complicated history. In previous studies, researchers have attributed the emissions in the visible light region to the existence of impurities or structural defects (such as oxygen vacancies, zinc vacancies, zinc interstitials, surface states). However, there are still certain differences. For quantum dots (QDs) with good crystallinity and high luminous efficiency, it is contradictory to attribute their emission mechanism in the visible light region to the defect model. This paper proposes a multiple bright singlet/triplet hybrid self-trapped exciton emission model for ZnO QDs, whose luminescence range covers from 400 nm to 700 nm. The Photoluminescence quantum yield (PLQY) of singlet exciton and triplet exciton emission are 45.56% and 22.44%, respectively. Thanks to their good transparency and bright triplet excitons, we have explored the X-ray detection imaging by ZnO QDs as scintillator. The lowest detection limit of the ZnO QD scintillator for X-ray is as low as 64.89 nGy/s, which is lower than the dose required for X-ray medical imaging. This work puts forward a new model for visible emission in ZnO QDs, demonstrating a new type of transparent scintillator and their potential application in X-ray imaging.
SHI Jiajuan, SHAN Xuanyu, WANG Zhongqiang, XU Haiyang, LIU Yichun
DOI:10.37188/CJL.20240331
摘要:Memristors have potential in high-efficiency information processing and synaptic function simulation due to their high density, low power consumption and continuously adjustable resistance. Zinc oxide is an ideal choice for memristor with high performance due to its various preparation methods, exciton stability and biocompatibility. Herein, the recent research progress of ZnO-based memristive device is reviewed, including memristive behaviors and mechanism, the cognitive functions of synapse simulated by analog-type memristor as well as functionality and applications. We first review the switching-type and corresponding memristive mechanism, including electronic memristors and optoelectronic memristors. Then, the cognitive functions of synapse including synaptic plasticity and learning experience are introduced. Moreover, we exhibit the applications of ZnO-based memristive device in logic operation, pattern recognition and multimodal in-sensor computing. Finally, we summarize the advantages/challenges of ZnO-based memristor and prospect the future development.
ZHAO Yuanyuan, ZHANG Yunxia, LIU Naiming, LIU Shengzhong, LIU Yucheng
DOI:10.37188/CJL.20240196
摘要:X-ray detection has been extensively used in medical diagnosis, security inspection, and industrial non-destructive detection etc. In recent years, metal halide perovskite X-ray detectors have attracted much attention due to their advantages such as high sensitivity, low detection limit and low cost. Compared with polycrystalline perovskite films, single crystal perovskites exhibit much lower trap density, higher carrier mobility-lifetime product, better uniformity and stability due to absence of grain boundaries, which are conducive to boost the performance of X-ray detectors. In this review, we first introduce the basic principle and the key performance parameters of X-ray detection to clarify the advantages of single crystal perovskite for direct X-ray detectors. Then, we review the research progress of single crystal perovskite direct X-ray detection and imaging. Specifically, the influence of crystal quality, composition regulation and structure of device of the single crystal perovskite on X-ray detection performance are systematically analyzed. Finally, we discussed the technical challenges and potential solutions faced by single crystal perovskite X-ray detectors, and provided a brief outlook on the development trends in the field.
WU Xuan, GAO Runlong, LIU Zhiyu, ZHONG Xiangli, LIU Linyue, OUYANG Xiaoping
DOI:10.37188/CJL.20240312
摘要:High-performance semiconductor X-ray detectors prefer outstanding characteristics including low detection of limit, low dark current, high sensitivity, fast response time, high radiation hardness and so on. Wide-bandgap semiconductors such as silicon carbide (SiC), gallium nitride (GaN), diamond, gallium oxide (Ga2O3), and zinc oxide (ZnO) exhibit exceptional properties, including a wide bandgap, high electron mobility, high breakdown field strength, high saturated carrier drift velocity, and large displacement energy. These characteristics enable them to demonstrate superior performance in X-ray detection, meeting the requirements for high-performance semiconductor X-ray detectors and making them highly promising candidates for such applications.As a result, they have emerged as promising candidates for advanced X-ray detectors.In this paper, the electrical properties, preparation technology and detection performance of SiC, GaN, diamond, Ga₂O₃, ZnO X-ray detectors are introduced, and the latest research is discussed. Meanwhile, future research directions and potential applications of wide-bandgap semiconductor X-ray detectors in medical imaging, industrial detection and space exploration conduct in-deep thinking.