Self‐Powered PbS CQDs Photodiode for High‐Resolution Underwater NIR Single‐Pixel Imaging

Abstract Underwater imaging (UI) technology is of considerable importance in scientific, economic, and societal contexts. The utilization of underwater near‐infrared (NIR) single‐pixel imaging (SPI) has been posited as a potentially viable alternative to conventional imaging systems. Here, the successful utilization of a high‐performance, self‐powered PbS colloidal quantum dots photodetector (PbS CQDs‐PD) is used as a single‐pixel photodetector within an underwater SPI system, is demonstrated. The development of a functional ligand engineering strategy has enabled the self‐powered PbS CQDs‐PD exhibiting remarkable performance metrics, including an ultralow dark current density of 1.3 × 10 −9 A cm − 2 , a responsivity up to 0.6 A W −1 , and an outstanding detectivity of 5.57 × 10 13 Jones. The high‐resolution images with 128 × 128 pixels are successfully achieved even at a 1% sampling rate, both in transmission and reflection modes, without the necessity of employing an additional filtering circuitry. It is noteworthy that high‐quality images with a signal‐to‐noise ratio (SNR) greater than 20 dB are obtained, even in turbid water conditions. In particular, a sufficiently discernible image can also be reconstructed based on reflection‐mode under turbid water conditions. This work represents a significant advancement in the field of underwater NIR SPI, paving the way for its practical implementation in further real‐world applications.