Fully transparent InZnSnO/β-Ga2O3/InSnO solar-blind photodetectors with high schottky barrier height and low-defect interfaces

Abstract

Ultra-wide bandgap beta-Ga2O3 photodiodes have received great attention due to transparent solar-blind deep ultraviolet photodetectors. We demonstrated an all oxide-based single-crystal beta-Ga2O3 photodiode in-corporated with transparent conductive InZnSnO and InSnO as Schottky and Ohmic contacts, respectively. High work function and low resistivity of InZnSnO allow for clear rectifying characteristics with a low dark current (< 0.1 nA) of up to -100 V of reverse bias. The Schottky barrier height and junction defects at the Schottky interface were modified using post-annealing treatment, thereby influencing the deep ultraviolet photoresponse. The responsivity of the annealed device was 9.6 mA/W, decreasing the Schottky barrier height engineering, while the photo responding speed was degraded and caused a persistent photocurrent effect due to the generation of defect states. (C) 2021 Elsevier B.V. All rights reserved.