All-Oxide NiO/Ga 2 O 3 p–n Junction for Self-Powered UV Photodetector

作者：Yachao Wang, Chao Wu, Daoyou Guo, Peigang Li, Shunli Wang, Aiping Liu, Chaorong Li, Fengmin Wu, Weihua Tang · 发表于：ACS Applied Electronic Materials · 年份：2020 · DOI：10.1021/acsaelm.0c00301 · 被引用次数：276 · 研究领域：Ga2O3 and related materials、ZnO doping and properties、Advanced Photocatalysis Techniques

Recently, Ga 2 O 3 -based self-powered ultraviolet photodetectors have aroused great interest due to their potential applications in civil, medical, and environmental monitoring fields. So far, most p–n junction photodetectors are fabricated with p-type semiconductors like GaN and SiC, which are usually nonoxide materials. As a result, the p-type semiconductors are oxidized and the conductive properties degenerated when constructing a p–n junction with the Ga 2 O 3 thin film at a high growth temperature. In this work, we chose the oxide NiO as the p-type material and used radio-frequency reactive magnetron sputtering system to fabricate the all-oxide NiO/Ga 2 O 3 p–n junction at room temperature and manufacture the self-powered UV photodetector. Thanks to the type II band alignment, the photodetector exhibits a responsivity ( R ) of 57 μA/W, a detectivity ( D *) of 5.45 × 10 9 jones, and an I light / I dark ratio of 122 when exposed to a 254 nm light irradiation at 0 V. In addition, the photodetector based on the all-oxide NiO/Ga 2 O 3 p–n junction shows good stability and reproducibility in air, oxygen, and vacuum. Our results provide an inexpensive and suitable pathway for the mass production of self-powered UV photodetectors.