Ultrathin Non‐van der Waals Chromium Sulfide: Liquid Phase Exfoliation, Characterization, and Self‐Powered Photoelectrochemical Photodetector Application

Abstract In the search for new advanced 2D materials for technological applications and to expand the research of non‐van der Waals (non‐vdW) 2D electronic devices, this study presents a novel strategy for liquid phase exfoliation (LPE) of non‐vdW Cr 2 S 3 to produce Cr 2 S 3 nanosheets (NSs). By utilizing N ‐methyl‐2‐pyrrolidone (NMP), bulk Cr 2 S 3 is separated along the (001) plane, resulting in the formation of NSs with an average thickness of ≈3 nm. Various characterization techniques are applied to the Cr 2 S 3 material before and after LPE. Subsequently, the obtained Cr 2 S 3 NSs are integrated into a photoelectrochemical (PEC)‐type photodetector (PD) to evaluate the photoelectric conversion efficiency under varying conditions. The findings indicate that the developed PD exhibits a distinct self‐powered photodetection capability with a photocurrent ( P ph ) of 39.5 nA cm −2 , a photoresponsivity ( R ph ) of 622 nA W −1 , and a detectivity ( D* ) of 0.5 × 10 7 Jones under 350 nm irradiation at 0 V. Moreover, the PD demonstrates rapid response time (0.06 s) and good long‐term stability (over 15 days), thus providing valuable insight for the advancement of non‐vdW Cr 2 S 3 ‐based optoelectronic devices.