Oxygen-vacancy-dependent high-performance-GaOnanorods photoelectrochemical deep UV photodetectors.

GaOis a good candidate for deep ultraviolet photodetectors due to its wide-bandgap, good chemical, and thermal stability. GaO-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-GaOwas proposed to obtain high-performance PEC photodetectors. The-GaOnanorods were synthesized by a simple hydrothermal method with an annealing process. The final samples were named as GaO-400, GaO-500, and GaO-600 for annealing at 400 ℃, 500 ℃, and 600 ℃, respectively. Different annealing temperatures lead to different Vconcentrations in the-GaOnanorods. The responsivity is 101.5 mA Wfor GaO-400 nanorod film-based PEC photodetectors under 254 nm illumination, which is 1.4 and 4.0 times higher than those of GaO-500 and GaO-600 nanorod film-based PEC photodetectors, respectively. The photoresponse of-GaOnanorod film-based PEC photodetectors strongly depends on the Vconcentration and high Vconcentration accelerates the interfacial carrier transfer of GaO-400, enhancing the photoresponse of GaO-400 nanorod film-based PEC photodetectors. Furthermore, the-GaOnanorod film-based PEC photodetectors have good multicycle, long-term stability, and repeatability. Our result shows that-GaOnanorods have promising applications in deep UV photodetectors.