MXene-contact enhanced broadband photodetection in centimeter level GeS films

Abstract

The persistent pursuit of broadband photodetectors derives from their unique properties for promising applications such as optoelectronic devices, imaging sensors, and neuromorphic computing. Here, we fabricated high-performance, ultra-wide spectral response (250–1064 nm) and easy-processing spin-deposition photodetector based on amorphous germanium sulfide (a-GeS) films by using Ti3C2T x transparent electrodes as contacts. In addition, photodetectors based MXenes contacts have larger photocurrent compared with Au contacts because MXenes conductive films have larger photo-responsive active areas and the surface plasmon-assisted hot carriers generated by the laser irradiation on MXenes. As-prepared photodetectors based on MXenes electrodes exhibit a photo-to-dark current ratio of up to 3.91 × 102 under a bias of 8 V, coupled with the response speed of 59 ms, photoresponsivity (166 mA W−1) and high detectivity (4.41 × 1010 Jones). This work combining amorphous materials with highly conductive MXene film has excellent application prospects for ultra-wide spectral response optoelectronic devices.