A Highly Transparent β-Ga2O3 Thin Film-Based Photodetector for Solar-Blind Imaging

Abstract

Ultra-wide bandgap Ga2O3-based optoelectronic devices have attracted considerable attention owing to their special significance in military and commercial applications. Using RF magnetron sputtering and post-annealing, monoclinic Ga2O3 films of various thicknesses were created on a c-plane sapphire substrate (0001). The structural and optical properties of β-Ga2O3 films were then investigated. The results show that all β-Ga2O3 films have a single preferred orientation (2(_)01) and an average transmittance of more than 96% in the visible wavelength range (380–780 nm). Among them, the sample with a 90-minute sputtering time has the best crystal quality. This sample was subsequently used to construct a metal-semiconductor-metal (MSM), solar-blind, ultraviolet photodetector. The resulting photodetector not only exhibits excellent stability and sunblind characteristics but also has an ultra-high responsivity (46.3 A/W) and superb detectivity (1.83 × 1013 Jones). Finally, the application potential of the device in solar-blind ultraviolet imaging was verified.