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

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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 ϵ-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, ϵ-Ga2O3 prepared here is certified to be an excellent candidate material to perform high-performance solar-blind detection.