A self-powered flexible UV photodetector based on an individual ZnO-amorphous Ga2O3 core–shell heterojunction microwire

Abstract

Self-powered wide band gap semiconductor ultraviolet (UV) photodetectors based on one-dimensional (1D) micro/nanowires have attracted considerable attention on account of their wide potential applications. Here, amorphous Ga₂O₃ was sputtered onto a ZnO microwire at room temperature using magnetron sputtering to form a self-powered ZnO-amorphous Ga₂O₃ core–shell heterojunction microwire UV photodetector. The low temperature growth process of the Ga₂O₃ shell and its amorphous properties make the core–shell structure have a clear interface and it can maintain excellent performance stability under the condition of stress. The heterojunction device exhibits commendable rectifying properties with a rectification ratio of ∼20.7 at ±2 V. Furthermore, a high peak responsivity of 131.4 mA W⁻¹ at 265 nm and a fast response speed of <1 s can be observed at 0 V. Even more interestingly, the photoelectric performance of the device hardly changes under various bending conditions, indicating its potential for flexible applications. Our findings in this work open up a new pathway for the design of flexible, self-powered photodetectors.