Solar blind deep ultraviolet β-Ga2O3 photodetectors grown on sapphire by the Mist-CVD method

In this report, we demonstrate high spectral responsivity (SR) solar blind deep ultraviolet (UV) beta-Ga2O3 metal-semiconductor-metal (MSM) photodetectors grown by the mist chemical-vapor deposition (Mist-CVD) method. The beta-Ga2O3 thin film was grown on c-plane sapphire substrates, and the fabricated MSM PDs with Al contacts in an interdigitated geometry were found to exhibit peak SR>150A/W for the incident light wavelength of 254 nm at a bias of 20 V. The devices exhibited very low dark current, about 14 pA at 20 V, and showed sharp transients with a photo-to-dark current ratio>10(5). The corresponding external quantum efficiency is over 7 x 10(4%). The excellent deep UV beta-Ga2O3 photodetectors will enable significant advancements for the next-generation photodetection applications. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.