Self-Powered <i>β</i> -Ga <sub>2</sub> O <sub>3</sub> Solar-Blind Photodetector Based on the Planar Au/Ga <sub>2</sub> O <sub>3</sub> Schottky Junction
Yusong Zhi, Zeng Liu, Xulong Chu, Shan Li, Zuyong Yan, Xia Wang, Yuanqi Huang, Jun Wang, Zhenping Wu, Daoyou Guo, Peigang Li, Weihua Tang
Abstract
In this paper, asymmetric interdigital Ti and Au electrodes have been successfully patterned on the β -Ga 2 O 3 films which are prepared by metal-organic chemical vapor deposition. Both photoconductive and photovoltaic modes have been observed under ultraviolet illumination, respectively. The device exhibits a low current density of 0.32 nA cm −2 at 20 V in dark condition. As the 254 nm illumination intensity increases above 400 μ W cm −2 , the device exhibits obvious self-powered characteristics with a responsivity of 0.4 mA W −1 , providing a specific detectivity of 1.8 × 10 12 Jones, a fast response time ( τ d = 50 ms), and a high photo-to-dark current ratio of ∼10 5 . As the positive bias was applied to Au/Ga 2 O 3 contact, the photodetector presents an improved performance with a responsivity of ∼0.3 A W −1 and a specific detectivity of 2.2 × 10 14 Jones at −10 V, ultra-high photo to dark ratio (2 × 10 6 ∼ 9 × 10 7 ), and a response time of 160 ms. In one word, the simple structured, self-powered characteristics and decent performances of the detector suggest promising applications in solar-blind ultraviolet photoelectronic technology in multiple areas.