二维半导体自读出式高灵敏非制冷红外探测器件研究

The uncooled infrared detectors have wide applications in military and commercial products. Pyroelectric detector operating at room temperature is a typical uncooled infrared detector, which needs improvement in performance (detectivity), structure (thermal isolation), and signal processing modes. Two-dimensional (2D) semiconductors offer more opportunities for the development of new-type photodetectors due to their unique low-dimensional structure and singular physical properties. In this project, we purpose to combine ferroelectric materials with 2D semiconductors. The sensitivity of 2D semiconductors to the polarization of ferroelectric materials reads and amplifies efficiently pyroelectric signals. An uncooled infrared detector with high sensitivity can be achieved in the mid- to long-wave infrared range. By designing the interface between the 2D semiconductor and the ferroelectric material, the polarization characteristic and pyroelectric effect of the ferroelectric material are coupled with the charge transfer and the interface properties of the 2D semiconductor, thereby the sensitivity of the detector is greatly enhanced. Moreover, such devices also embrace the advantages of simple structure and ultra-low power consumption. Through the research of this project, it is expected to make a breakthrough in pyroelectric detectors from the structure, working principle and performance, and then provide theoretical and technical basis to meet the national major demand areas in military and commercial applications.

非制冷红外探测器在军事和民用等众多领域都具有重要应用。室温工作的热释电探测器属一类典型非制冷红外探测器，此类探测器在性能（如探测率）、结构（热隔离）以及信号处理模式上仍存改进和发展空间。二维半导体材料因其独特的低维结构及奇异物理性能，为研究新型光电探测器提供更多可能性。本项目拟提出将具有铁电特性的热释电材料与二维半导体相结合，利用二维半导体对铁电材料极化的敏感特性，可对其热释电信号进行高效读出和放大，有望实现中波至长波红外波段高灵敏光响应的非制冷红外探测器。通过对二维半导体和铁电材料的异质界面设计，将铁电材料的极化特性、热释电效应与二维材料的半导体电荷输运行为、界面特性等多机制耦合，突破器件灵敏度提升的瓶颈。同时，此类器件还具有结构简单、低功耗等特点。通过项目研究，有望从器件结构、机理及性能上对现有热释电类探测器形成突破，为此类器件在国家重大需求领域的应用提供理论基础和技术支撑。

随着红外探测技术的不断发展，以小型化、低功耗、宽光谱为特征的探测技术一直是该领域前沿研究的重要方向。本项目针对基于热释电效应的非制冷红外探测器性能提升，提出将铁电材料与二维半导体相结合，一方面通过铁电极化电场抑制二维半导体的载流子浓度，降低器件暗电流；另一方面通过二维半导体读出并放大铁电热释电电流，使器件在中波至长波范围的探测灵敏度得到提升，器件的光谱响应范围覆盖375 nm-12 μm，在中波至长波范围的峰值探测率达到6×109 cmHz1/2/W，响应时间为5.5 ms。此外，通过铁电材料提供的极化场调控半导体异质结的能带类型，研制了及高速高灵敏、宽光谱和偏振探测多功能于一体的新型红外探测器。在此基础上，利用极化场调控各向异性半导体材料，调控其能带结构的非对称性，结合铁电畴构建的面内PN结，实现了偏振灵敏度的极大提升。本项目为改善热释电探测器的灵敏度提供新思路，为发展具有高灵敏、多功能和多维信息获取的新一代红外探测器奠定基础。相关研究成果在Nature Communications、Science Advances等期刊发表学术论文9篇，申请中国发明专利3项（授权2项），申请美国发明专利2项（授权1项）。