Ultrahigh Photo-Responsivity and Detectivity in 2D Bismuth Sulfide Photodetector for Vis-NIR Radiation.

Bismuth sulfide (BiS) exhibits a direct energy bandgap and an exceptional optical absorption capability over a broadband radiation, thus presents a novel class of 2D photodetector material. The field effect transistor (FET) photodetector device is fabricated from 2D BiS. An anomalous variation in the transport characteristics of 2D BiS is observed with the variation in temperature.