Lu2O3: A promising ultrawide bandgap semiconductor for deep UV photodetector

Abstract

Lutetium oxide (Lu2O3), an ultrawide semiconductor with an intrinsic bandgap of 5.5-5.9 eV, has been proposed as a potential material for a high- performance deep-ultraviolet (DUV) photodetector. Here, crystal oriented Lu2O3 films with bandgap of 5.6 eV are grown on GaN substrates through sputtering Lu2O3 target, based on which a graphene/Lu2O3/GaN DUV photovoltaic detector is constructed with its photoelectric performance being systematically studied. According to our research, under 0 V bias and 185 nm DUV irradiation, this device shows a high photoresponsivity of ∼13.7 μA/W, a short response time of ∼0.4 s, and a high light to dark current ratio of >600, which is about 1 order of magnitude higher than that of a currently reported DUV photovoltaic detector based on other films grown by magnetron sputtering. This research helps to broaden the range of candidate materials for DUV photodetectors and can work as a significant reference to develop the technology for device fabrication.