1. Self-formed interfacial oxide layer minimizes reverse bias dark current in PbS colloidal quantum dot photodiodes.
- Author
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Yang, Qian, Huang, Hao-Wen, Xu, Gao, Yuan, Yu, Jiang, Meng-Ting, Zhong, Ya-Nan, Gao, Xu, Xu, Jian-Long, and Wang, Sui-Dong
- Subjects
SEMICONDUCTOR nanocrystals ,PHOTODIODES ,SPECTRAL sensitivity - Abstract
PbS colloidal quantum dot (CQD) photodiodes possess high photoresponsivity and broad spectral sensitivity, making them tremendously attractive for low-cost short-wave infrared (SWIR) sensing. A critical challenge in achieving high detectivity in SWIR photodiodes is to minimize their reverse bias dark current density (J
dark ) and elucidate the origin of Jdark . We demonstrate in this work how the self-formed AlOx at the ZnO/Al interface dramatically reduced Jdark of the PbS CQD SWIR photodiodes. In such a simple and controlled way, the interfacial states were thoroughly passivated by post-exposure to dry air, which could block the dominant pathways for minority hole injection from Al electrode. The treated photodiode showed low Jdark down to 1.58 × 10−7 A/cm2 at –0.5 V, high photoresponsivity of 0.62 A/W, and high specific detectivity of 2.05 × 1012 Jones at 1413 nm, establishing a readily approach to optimizing detectivity in PbS CQD SWIR photodetectors. [ABSTRACT FROM AUTHOR]- Published
- 2023
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