Humidity-Resistant\nSolar-Blind Ultraviolet Photodetectors\nBased on Solution-Processed Amorphous Scandium Oxide Films

Abstract

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