Self‐Powered and Broadband Photodetector Based on SnS₂/ZnO_1−xS_x Heterojunction

Abstract

Abstract Self‐powered photodetectors that can work without an external power source are expected to play a crucial role in future optoelectronic devices. Herein, SnS 2 /ZnO 1− x S x heterojunctions are fabricated by a facile sputtering method and constructed as self‐powered broadband photodetectors covering from UV (365 nm) to NIR (850 nm). The self‐powered device shows a superior responsivity of 8.28 mAW −1 , a photodetectivity of 5.09 × 10 10 Jones, and a high I on / I off ratio of 1.08 × 10 5 at 365 nm. Furthermore, the SnS 2 /ZnO 0.7 S 0.3 heterojunction device presents a fast response speed with a rise time of 49.51 ms and a decay time of 25.93 ms. The high performance of the device is attributed to the type II band alignment of the heterojunction as well as the Schottky barrier. The high responsivity, fast response speed, large I on / I off ratio, and broadband response enable the SnS 2 ‐based heterojunction a potential candidate for self‐powered photodetectors in the range from UV to NIR.