GaN UV photodetector by using transparency antimony-doped tin oxide electrode

Abstract

GaN metal–semiconductor–metal (MSM) ultraviolet photodetectors with antimony-doped tin oxide (ATO) transparent electrodes were fabricated and characterized. The ATO films with the thickness of 750 nm were deposited on GaN substrates by RF magnetron sputtering. The main X-ray peak of ATO film was identified as (1 0 1) using the X-ray diffraction (XRD) technique. The barrier height between ATO and GaN was determined to be 1.12 eV. Finally, the responsivity of undoped GaN-based MSM photodetectors with ATO electrodes measured at 325 nm under the bias voltage of 1 and 5 V was 0.051 and 0.095 A W −1, respectively.