Humidity-Resistant Solar-Blind Ultraviolet Photodetectors Based on Solution-Processed Amorphous Scandium Oxide Films

Scandium oxide (Sc2O3) is an ultrawide band gap (5.2–6.3 eV) semiconductor with excellent heat and moisture resistance, which has great potential for being applied to high-performance solar-blind ultraviolet (SBUV) photodetectors. In this work, an amorphous-Sc2O3 (ScOx) film was prepared by a solution method and used as a photosensitive layer of SBUV photodetectors. Based on the Pt/ScOx Schottky junction, a humidity-resistant ScOx SBUV photodetector was fabricated on a highly doped GaN substrate (n+-GaN) with excellent performance exhibited, including a high photoresponsivity of 5.77 mA/W as well as a high detectivity of 1.73 × 1011 Jones at 0 V bias and under 258 nm irradiation. Meanwhile, a characteristic of good humidity resistance exhibited by this device after a long-term placement (more than 2 weeks) at high humidity of 85% is very significant for the operation in an environment with variable humidities. This study can help to promote the application of Sc2O3 in the field of photodetectors and provide an option for the materials needed for the preparation of SBUV photodetectors.