Self-Powered beta-Ga2O3 Solar-Blind Photodetector Based on the Planar Au/Ga2O3 Schottky Junction

In this paper, asymmetric interdigital Ti and Au electrodes have been successfully patterned on the beta-Ga2O3 films which are prepared by metal-organic chemical vapor deposition. Both photoconductive and photovoltaic modes have been observed under ultraviolet illumination, respectively. The device exhibits a low current density of 0.32 nA cm(-2) at 20 V in dark condition. As the 254 nm illumination intensity increases above 400 mu W cm(-2), the device exhibits obvious self-powered characteristics with a responsivity of 0.4 mA W-1, providing a specific detectivity of 1.8 x 10(12) Jones, a fast response time (tau(d)= 50 ms), and a high photo-to-dark current ratio of similar to 10(5). As the positive bias was applied to Au/Ga2O3 contact, the photodetector presents an improved performance with a responsivity of similar to 0.3 A W-1 and a specific detectivity of 2.2 x 10(14) Jones at -10 V, ultra-high photo to dark ratio (2 x 10(6)similar to 9 x 10(7)), and a response time of 160 ms. In one word, the simple structured, self-powered characteristics and decent performances of the detector suggest promising applications in solar-blind ultraviolet photoelectronic technology in multiple areas. (c) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.