Single-layer graphene electrode enhanced sensitivity and response speed of β-Ga2O3 solar-blind photodetector

High-sensitivity, rapid response beta-Ga2O3 film-based metal-semiconductor-metal (MSM) solar-blind photodetectors were obtained by replacing conventional Aufri electrodes with single-layer graphene (SLG) nanosheets. Compared with the photodetector with Aufri electrodes, the photodetector using SLG electrodes demonstrates enhanced deep ultraviolet photoresponse properties, including a more rapid response speed (0.078 s), a higher light-to-dark current ratio (similar to 1.41 x 10(4%)), a higher R-254/R-365 rejection ratio (similar to 1020), and the larger detectivity (similar to 6.29 x 10(11) Jones). The integration of SLG with beta-Ga2O3 offers a large transparent area to the incident photons, and narrows the barrier at the contact interface upon ultraviolet illumination, strongly suggesting an unlimited potential for deep ultraviolet optoelectronic devices. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement