超宽禁带半导体氧化镓基X射线探测器的研究进展

X射线具有波长短、穿透能力强等优点,在医学成像、安全检查、科学研究、空间通信等领域具有重要作用。半导体X射线探测器可以将X射线转换为电流信号,具有易集成、空间分辨率高、能量分辨率高、响应速度快等优点。高性能的X射线探测器应具备暗电流低、灵敏度高、响应速度快、可长时间稳定工作等特点,因此制备X射线探测器的半导体材料应具有电阻率高、缺陷少、抗辐照能力强、禁带宽度宽等性质。氧化镓(Ga₂O₃)是一种新型宽禁带半导体材料,具有超宽禁带宽度、高击穿场强、高X射线吸收系数、耐高温、可采用熔体法生长大尺寸单晶等优点,是一种适合制备X射线探测器的新型材料,近年来基于Ga₂O₃的X射探测器成为辐射探测领域的研究热点之一。本文主要介绍了Ga₂O₃半导体的物理性质及其在X射线探测器方面的研究进展,分析了影响X射线探测器性能的物理机制,为提高Ga₂O₃基X射探测器的性能提供了思路。

Research Progress of Ultra-Wide Band Gap Semiconductor Ga2O3-Based X-Ray Detectors

X-ray with its advantages of short wavelength and strong penetration plays an important role in medical imaging, security inspection, scientific research, space communication, and other fields. Semiconductor X-ray detectors can convert X-ray photons into current signals, which have the advantages of easy integration, high spatial resolution, high energy resolution, and fast response speed. High-performance X-ray detectors should have the features of low dark current, high sensitivity, fast response speed, and stable work for a long time. Therefore, the semiconductor materials for preparing X-ray detectors should have the characteristics of high resistivity, few defects, and strong irradiation resistance. Gallium oxide (Ga₂O₃) is one of the new wide band gap semiconductor materials, which has the advantages of ultra-wide band gap, high breakdown field strength, high X-ray absorption coefficient, high thermal stability, and being grown by melting methods. Therefore, Ga₂O₃ is suitable for preparing X-ray detectors. In recent years, X-ray detectors based on Ga₂O₃ have become one of the research hotspots. In this review, the physical properties of Ga₂O₃ semiconductor and its research progress in X-ray detectors are introduced, the influence mechanism of materials and device structure on the performance of X-ray detectors are analyzed, the ideas for the preparation of Ga₂O₃-based X-ray detectors with high performance are provided.