Study on PECVD-hetero-grown β-Ga2O3 thin film and temperature-modulated solar-blind UV photodetection

Abstract

Using a convenient and low-cost plasma-enhanced chemical vapor deposition technique, uniform Ga2O3 thin films were hetero-grown on c-plane sapphire substrates at different temperatures, with a root mean square roughness as low as 2.71 nm and a growth rate of up to 1121.30 nm h−1; and then the solar-blind UV photodetection performances were discussed in detail. Metal-semiconductor-metal solar-blind UV photodetectors (PDs) based on the five Ga2O3 films prepared at different temperatures exhibit ultra-low dark currents (I dark) ranging among 22–168 fA. Under the illumination of 254 nm UV light, the PD prepared by the film grown at 820 °C possesses the highest performance, with a high photo-to-dark current ratio of 1.47 × 105, a low rise/decay time of 0.067/0.13 s, a specific detectivity (D *) of 3.56 × 1012 Jones, and a linear dynamic range of 92.89 dB. Overall, the results in this work may well provide a referable method for growing cost-effective and ultralow-noise Ga2O3 thin films, as well as achieving decent solar-blind UV sensing applications.