Low-temperature processed high-performance visible–transparent Ga2O3 solar blind ultraviolet photodetectors with the indium–tin–oxide electrode

Abstract

High-performance visible–transparent electronics are being used as emerging technologies in next-generation ‘see-through’ devices. In this work, the high-performance fully visible–transparent metal–semiconductor-metal (MSM) interdigitated Ga2O3 solar blind ultraviolet (UV) photodetector (PD) was successfully fabricated by using the ITO electrode. The Ga2O3 film and the ITO electrode were grown on the sapphire substrate by the radio frequency magnetron sputtering method at a low temperature. It is demonstrated that the Ga2O3 film is the single crystal film with the (−201) crystal plane orientation, and its bandgap can be obtained around 4.8 eV. Compared with the control tradsitional opaque PD with the Ti/Au metal electrode, the fully visible–transparent solar blind UV PD with the ITO electrode showed a larger photocurrent of 1.8 µA and responsivity of 181.03 A W−1 at the bias voltage of 20 V. The external quantum efficiency (EQE) even reached 88 198%, and photo-to-dark current ratio achieved 4.8 × 105. Besides, the PD with the ITO electrode also had a shorter response time and good electrical stability after multiple light cycles. The fabricated fully visible–transparent Ga2O3 solar blind UV PD is among the best reported Ga2O3 UV PDs and shows the great potential for the next generation of ‘see-through’ functional devices.