0D/2D PbS/1T‐CrS 2 Heterostructure for High‐Performance Ultraviolet to Near‐Infrared Detection

ABSTRACT Zero‐dimensional (0D) lead sulfide (PbS) quantum dots (QDs), with their size‐tunable bandgaps, hold great promise for high‐efficiency photodetection across a broad spectral range. However, the presence of surface ligands on colloidal PbS QDs and their inherently isolated states hinder efficient carrier transport. In contrast, two‐dimensional (2D) materials such as metallic 1T‐phase CrS 2 , which are free of dangling bonds, can serve as highly effective carrier transport channel. Here, a strategy for constructing high‐performance photodetectors based on ligand‐free PbS QDs, achieved by converting a PbI 2 film into PbS QDs on a novel 2D metallic 1T‐CrS 2 layer, is proposed. By combining the metallic character of 1T‐CrS 2 with the strong optical responsivity of 0D PbS QDs and theoretically predicted low‐resistance contact at the PbS‐QDs/1T‐CrS 2 interface, this research demonstrates a stable broadband photodetector with outstanding performance such as responsivity (95.1 A/W@1550 nm and 2.7 A/W@375 nm) and a sub‐millisecond response time (0.31 ms@1550 nm and 0.69 ms@375 nm). This heterostructure utilizes the 0D PbS QDs as the photoactive layer and 1T‐CrS 2 as an efficient carrier transport medium, synergistically enhancing the overall photodetection performance. This study opens a new avenue for designing high‐performance, broadband photodetectors leveraging quantum dot‐2D material heterostructures.