Oxygen-vacancy-dependent high-performance α-Ga2O3nanorods photoelectrochemical deep UV photodetectors

Lihang Qu; Jie Ji; Xin Liu; Zhitao Shao; Mengqi Cui; Yunxiao Zhang; Zhendong Fu; Yuewu Huang; Guang Yang; Wei Feng

doi:10.1088/1361-6528/acbfbd

Oxygen-vacancy-dependent high-performance α-Ga₂O₃nanorods photoelectrochemical deep UV photodetectors

Nanotechnology. 2023 Mar 14;34(22). doi: 10.1088/1361-6528/acbfbd.

Authors

Lihang Qu¹, Jie Ji¹, Xin Liu¹, Zhitao Shao¹, Mengqi Cui¹, Yunxiao Zhang², Zhendong Fu², Yuewu Huang³, Guang Yang¹, Wei Feng¹

Affiliations

¹ College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, People's Republic of China.
² Tianjin Jinhang Technical Physics Institute, Tianjin, 300308, People's Republic of China.
³ College of Materials Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150080, People's Republic of China.

PMID: 36854175
DOI: 10.1088/1361-6528/acbfbd

Abstract

Ga₂O₃is a good candidate for deep ultraviolet photodetectors due to its wide-bandgap, good chemical, and thermal stability. Ga₂O₃-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_o) engineering towardsα-Ga₂O₃was proposed to obtain high-performance PEC photodetectors. Theα-Ga₂O₃nanorods were synthesized by a simple hydrothermal method with an annealing process. The final samples were named as Ga₂O₃-400, Ga₂O₃-500, and Ga₂O₃-600 for annealing at 400 ℃, 500 ℃, and 600 ℃, respectively. Different annealing temperatures lead to different V_oconcentrations in theα-Ga₂O₃nanorods. The responsivity is 101.5 mA W^-1for Ga₂O₃-400 nanorod film-based PEC photodetectors under 254 nm illumination, which is 1.4 and 4.0 times higher than those of Ga₂O₃-500 and Ga₂O₃-600 nanorod film-based PEC photodetectors, respectively. The photoresponse ofα-Ga₂O₃nanorod film-based PEC photodetectors strongly depends on the V_oconcentration and high V_oconcentration accelerates the interfacial carrier transfer of Ga₂O₃-400, enhancing the photoresponse of Ga₂O₃-400 nanorod film-based PEC photodetectors. Furthermore, theα-Ga₂O₃nanorod film-based PEC photodetectors have good multicycle, long-term stability, and repeatability. Our result shows thatα-Ga₂O₃nanorods have promising applications in deep UV photodetectors.

Keywords: Ga2O3; nanorods; oxygen vacancy; photodetector; photoelectrochemical.