Fabrication of -Ga2O3 solar-blind photodetector with symmetric interdigital Schottky contacts responding to low intensity light signal

Abstract

Owing to the constraint of carrier transport, the dark current is relatively lower in Schottky contacted devices than that in Ohmic contacted devices, leading to a high specific detectivity in photodetectors. In this work, we prepared -Ga2O3 thin film by using metal-organic chemical vapor deposition, then constructed a three-pair interdigital ultraviolet solar-blind photodetector with Au electrodes as Schottky contacts. Seen from the results, this photodetector displays an outstanding wavelength selectivity with responsivity of 0.52 A W-1 responding to 250 nm wavelength light. In addition, it shows a photo-to-dark current ratio of 1.82 × 104/6.03 × 102 at 5 V under 40/5 μW cm-2 254 nm light illuminations, respectively, and a low dark current of 1.87 × 10-11 A. Correspondingly, the specific detectivity is 1.67 × 1013/4.45 × 1012 Jones, and the photoresponsivity is 0.198 A W-1/52.54 mA W-1. Overall, -Ga2O3 prepared here is certified to be an excellent candidate material to perform high-performance solar-blind detection.