硫化铅量子点（PbS QD）光电探测器由于其低温溶液加工性及优异近红外性能，有望与CMOS集成实现低成本、高质量近红外成像。本项目基于申请人及所在课题组在PbS QD光电探测器方面的前期工作，开展面向近红外成像的PbS QD光电二极管研究。PbS QD光电二极管与 CMOS集成有两大瓶颈：i）高缺陷浓度导致大尺寸（吸收峰>1300 nm）PbS QD器件的暗电流过高；ii）仅有的单PN结PbS QD器件无法通过CMOS时序电路调控实现全局快门，不利于动态成像。申请人拟根据PbS QD表面Pb/S比随尺寸变化规律设计针对大尺寸PbS QD特异性液相配体交换，通过混合阴阳离子配体钝化缺陷，降低器件暗电流；构筑双PN结的NPN结构PbS QD器件，利用其双极性特性，实现“快门-探测一体化”。本项目为开发PbS QD/CMOS近红外成像芯片打下坚实基础。

Lead sulfide quantum dot (PbS QD) photodetectors are expected to integrate with CMOS to achieve low-cost, high-quality near-infrared imaging due to their low temperature solution processability and excellent near-infrared performance. Based on the preliminary work on PbS QD photodetectors of the applicant and the research group, this project conduct the study on PbS QD photodiodes for near-infrared imaging. When integrated with CMOS, PbS QD photodiodes have two major bottlenecks: i) high defect concentration results in large-size (absorption peak >1300 nm) PbS QD devices with too high dark current; ii) alternative single PN-junction PbS QD devices could not realize global shutter through the control of CMOS sequential circuit, which is detrimental for dynamic imaging. Applicant intends to design specific liquid-phase ligand exchange for large-size PbS QD according to the surface Pb/S ratio, and adopt mixed anion-cation ligands to passivate defects and reduce dark current; construct double PN-junction NPN structure PbS QD device and utilize its bipolar nature to achieve "shutter-detection integration". This project lays a solid foundation for the development of PbS QD/CMOS near-infrared imaging chips.