基于II-VI族低维半导体结构的高性能耗尽型和存储型光电探测器的制备与机理研究

弱光探测在夜视、遥感、天文观测和量子通讯等领域具有重要应用。目前商用弱光探测器主要包括光电倍增管和雪崩二极管等，它们通常尺寸较大，需要高工作电压，与数字成像系统中的微电子电路难以兼容。本项目以发展高探测度和高弱光探测灵敏度为目标，系统开展II-VI族低维半导体的表界面调控及高性能纳米光电探测器的制备和机理研究。以调控表面态为目的进行II-VI族低维半导体的可控制备，利用表面态处理、表面掺杂、表面修饰等手段调控II-VI族低维半导体的光电性能，建立表界面调控与光电性能之间的相互关系。在此基础上，通过表界面调控构筑基于II-VI族低维半导体的高探测率和高弱光探测灵敏度的耗尽型和存储型光电探测器，研究新型器件的工作机理，重点探究表界面调控对器件的影响机制。本项目提出了基于低维半导体材料的新概念弱光探测器，项目的开展将有望突破性提升纳米光电探测器的弱光探测能力，对纳米光电探测器的应用具有重要意义。

Ultraweak light detectors have wide-ranging important applications such as astronomical observation, remote sensing, laser ranging, and night vision. Current commercial ultraweak light detectors are commonly based on a photomultiplier tube or an avalanche photodiode, and they are incompatible with microelectronic devices for digital imaging applications, because of their high operating voltage and bulky size. In this project, we will systematically investigate the property tuning and high-performance photodetectors of low-dimensional group II-VI semiconductor nanostructures via surface engineering. The controllable preparation of low-dimensional group II-VI semiconductor nanostructures will be conducted for the purpose of adjusting their surface states. The electronic and optoelectronic properties will be rationally tuned by surface engineering strategy including surface state treatment, surface doping, and surface modification. Furthermore, high-detectivity and high-sensitivity full-depleted and memory photodetectors will be constructed and optimized. We will study the working mechanism and photoelectric conversion law of the new-type photodetector, especially focusing the direct characterizations of surface effects. This project offers a design concept for ultraweak light sensing devices, and will overcome the performance bottleneck of low-dimensional nanostructure-based photodetectors, thus presenting significant advance towards the development of ultraweak light sensors.