Zero-biased deep ultraviolet photodetectors based on graphene/cleaved (100) Ga2O3 heterojunction

In this paper, fast rcsponsc, zero-biased, solar-blind UV photodetectors based on graphene/beta-Ga2O3 hetcrojunctions were fabricated by transferring a monolayer graphene onto fresh cleaved beta-Ga2O3 (100) single crystal substrate. At zero bias, the photo responsivi at 254 mu and the UV/visible rejection ratio (R-235 nm/R-400 nm) and the response time are obtained to be 10.3 mA/W and 2.28 x 10(2) and 2.24 mu s, respectively. for the graphene/beta-Ga2O3 (100) detector. The fast response and the high sensitivity can be attributed to the high mobility and UV transparency of graphene top-electrode and the low defect density of the beta-Ga2O3 (100) cleaved surface. Such zero-biased detectors are vei promising for next generation solar-blind UV photodetection. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement