Electrode Engineering of Colloidal Quantum Dot Photodetectors Using a Self-Assembled Island-like LiF Interfacial Layer

• DOI: 10.1021/acsphotonics.4c00066
• Publication Date: 2024-03-20T13:20:27Z
• Authors: Ya Wang; Huicheng Hu; Xi Ran; Long Chen; Mengxuan Yu; Peilin Liu; Jungang He; Jianbing Zhang; Liang Gao; Jiang Tang; Xinzheng Lan

Lead sulfide (PbS) colloidal quantum dot (CQD) photodetectors (PDs) are promising devices for low-cost, high-performance, and large-area infrared imaging. To achieve commercial applications, it is necessary not only to further improve performance but also high stability. In this study, the uncontrolled migration of Au element into PbS CQD layers was identified. An interface passivation approach employed, which involved implementation a self-assembled island-like LiF interfacial layer between PbS-EDT electrode. The effectively mitigated detrimental substantively enhanced stability PDs. At same time, strategy substantially suppressed dark current in PDs due passivation, led more than 2-fold improvements specific detectivity 4.8 × 1012 Jones. A photodiode imager based on thin-film transistor readout circuit finally fabricated. Penetration imaging material discrimination were demonstrated successfully by imager.