Oxygen-vacancy-dependent high-performance α -Ga 2 O 3 nanorods photoelectrochemical deep UV photodetectors

• Published in: Nanotechnology 2023-05, Vol.34 (22), p.225203
• Main Authors: Qu, Lihang, Ji, Jie, Liu, Xin, Shao, Zhitao, Cui, Mengqi, Zhang, Yunxiao, Fu, Zhendong, Huang, Yuewu, Yang, Guang, Feng, Wei
• Format: Article
• Language: English
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/acbfbd

Ga O is a good candidate for deep ultraviolet photodetectors due to its wide-bandgap, good chemical, and thermal stability. Ga O -based photoelectrochemical (PEC) photodetectors attract increasing attention due to the simple fabrication and self-powered capability, but the corresponding photoresponse is still inferior. In this paper, the oxygen vacancy (V ) engineering towards -Ga O was proposed to obtain high-performance PEC photodetectors. The -Ga O nanorods were synthesized by a simple hydrothermal method with an annealing process. The final samples were named as Ga O -400, Ga O -500, and Ga O -600 for annealing at 400 ℃, 500 ℃, and 600 ℃, respectively. Different annealing temperatures lead to different V concentrations in the -Ga O nanorods. The responsivity is 101.5 mA W for Ga O -400 nanorod film-based PEC photodetectors under 254 nm illumination, which is 1.4 and 4.0 times higher than those of Ga O -500 and Ga O -600 nanorod film-based PEC photodetectors, respectively. The photoresponse of -Ga O nanorod film-based PEC photodetectors strongly depends on the V concentration and high V concentration accelerates the interfacial carrier transfer of Ga O -400, enhancing the photoresponse of Ga O -400 nanorod film-based PEC photodetectors. Furthermore, the -Ga O nanorod film-based PEC photodetectors have good multicycle, long-term stability, and repeatability. Our result shows that -Ga O nanorods have promising applications in deep UV photodetectors.