Ambient-Stable and High On/Off Ratio Near-Infrared Photodetector Based on Perovskite-Treated PbS Colloidal Quantum Dots

Due to their low-cost in manufacturing, size-tunable spectral sensitivity, and flexible substrate compatibility, lead sulphide colloidal quantum dots (PbS CQDs) are increasingly regarded as promising active material candidates for next-generation NIR photodetectors. In this study, the effective passivation on the surface of PbS CQDs with perovskites is demonstrated, and the perovskite-treated PbS CQDs show improved ambient stability and reduced agglomeration. The PbS CQDs photodiode detectors are self-powered and exhibit a high on/off ratio up to 3×10
⁴
along with a large photocurrent density of 2 mA cm
^-2
. Meanwhile, the photoconductor structured photodetectors based on the same materials, displays a responsivity of 0.48 A W
^-1
and excellent long-term stability in ambient atmosphere.