面向CMOS集成的PbS体相薄膜结型红外焦平面探测器研究

短波红外成像技术具有穿透力强、识别度高、全天候适应等特点，被广泛应用于军事和民用领域，具有重要的战略意义和经济价值。当前主流的商用铟镓砷短波红外焦平面探测器存在工艺复杂、成本高昂、核心技术被国外垄断等问题，难以大规模推广。硫化铅（PbS）体相薄膜具有禁带宽度合适（0.41 eV）、吸收系数大（>104 cm−1）、载流子迁移率高（>500 cm2/V·s）、易与CMOS集成和稳定性佳等优势，具有实现低成本、高性能短波红外探测及成像的巨大潜力。但目前PbS薄膜探测器多采用光电导型器件结构，存在暗电流大、探测性能差等问题。本项目基于前期工作积累，面向CMOS一体化集成的需求，拟采用化学水浴法获得高质量PbS薄膜，并引入掺杂元素构建同质结器件，依靠结型器件的耗尽区来达到降低暗电流、提高探测性能的目的，最终实现暗电流密度<100 μA/cm2、面阵规模达640×512的短波红外焦平面探测器。

With the advantages of strong penetration, high recognition, and all-weather adaptability, short-wavelength infrared imaging technology is widely used in military and civil fields, showcasing important strategic significance and economic value. Currently, the mainstream commercial indium gallium arsenide (InGaAs) short-wavelength infrared focal plane detector is limited by complex manufacturing process, high cost, and monopolized core technology, thus it is difficult to promote on a large scale. Lead sulfide (PbS) bulk thin films have the advantages of suitable bandgap (0.41 eV), large absorption coefficient (>104 cm−1), high carrier mobility (>500 cm2/V·s), excellent integratability with CMOS, and good stability, demonstrating great potential to realize low-cost, high-performance short-wavelength infrared detection and imaging. However, at present, most of PbS thin-film detectors are based on photoconductive device structure, which suffer from large dark current and poor detection performance. Herein, on the basis of previous work and facing the needs of CMOS integration, this project plans to use chemical bath method to obtain high-quality PbS thin films, and introduce doping elements to construct homojunction devices. Depending on the depletion region of junction devices, the purpose of reducing dark current and improving detection performance can be achieved. Finally, we hope to realize a short-wavelength infrared focal plane detector with a dark current density <100 μA/cm2 and area array of 640×512.