Temperature-Dependent Self-Powered Solar-Blind Photodetector Based on Ag2O/beta-Ga2O3 Heterojunction

Abstract

In this study, a high-photoresponsivity self-powered deep ultraviolet (DUV) photodetector based on an Ag2O/beta-Ga2O3 heterojunction was fabricated by depositing a p-type Ag2O thin film onto an n-type beta-Ga2O3 layer. The device characteristics after post-annealing at temperatures ranging from 0 to 400 degrees C were investigated. Our DUV devices exhibited typical rectification characteristics. At a post-annealing temperature of 300 degrees C, the as-fabricated device had a low leakage current of 4.24 x 10(-11) A, ideality factor of 2.08, and a barrier height of 1.12 eV. Moreover, a high photo-responsivity of 12.87 mA/W was obtained at a 100 mu W/cm(2) light intensity at a 254 nm wavelength at zero bias voltage, the detectivity was 2.70 x 10(11) Jones, and the rise and fall time were 29.76, 46.73 ms, respectively. Based on these results, the Ag2O/beta-Ga2O3 heterojunction photodetector operates without an externally applied voltage and has high responsivity, which will help in the performance improvement of ultraviolet sensing systems.