A self-powered deep-ultraviolet photodetector based on an epitaxial Ga2O3/Ga:ZnO heterojunction

Abstract

A deep-ultraviolet photodetector (DUV PD) which can function independently of an external power supply is urgently desired for the next-generation photodetection applications from the viewpoint of being diminutive, convenient, and power saving. In this work, by introducing a lattice compatible semiconductor Ga:ZnO, a high quality β-Ga₂O₃/Ga:ZnO heterojunction based DUV PD is achieved using laser molecular beam epitaxy. The obtained device could operate in a self-powered mode with an excellent wavelength selectivity, a high ON/OFF ratio, a high DUV/visible rejection ratio, and a high stability under 254 nm light illumination. The physical mechanism responsible for the observation is discussed based on the photogenerated electron–hole pairs separated in the depletion region under the built-in electric field. Our work may provide a new insight into further high performance self-sufficient DUV PD applications.