A self-powered high-performance photodetector based on a MoS2/GaAs heterojunction with high polarization sensitivity

摘要

The rich variety and unique optoelectrical properties of two-dimensional (2D) layered nanomaterials allow researchers to design various photodetectors working at different wavelengths. In this study, a self-powered broadband photodetector was fabricated by constructing a heterojunction from a 2D MoS2 film and bulk GaAs. The MoS2/GaAs heterojunction photodetector demonstrated a wide response spectrum from deep ultraviolet (DUV) to near-infrared (NIR) with a high responsivity of 35.2 mA W-1, a high specific detectivity of 1.96 x 10(13) Jones and a fast response speed of 3.4/15.6 mu s at zero bias. Further investigation reveals that the MoS2/GaAs heterojunction photodetector shows high polarization sensitivity to a polarized optical signal with a peak-to-valley ratio of 4.8. Such high-performance and high polarization sensitivity of the MoS2/GaAs heterojunction photodetector indicate that it has great potential for photodetection in a complex environment.