Self-Powered Solar-Blind Photodetector with Fast Response Based on Au/β-Ga₂O₃ Nanowires Array Film Schottky Junction

Because of the direct band gap of 4.9 eV, β-Ga₂O₃ has been considered as an ideal material for solar-blind photodetection without any bandgap tuning. Practical applications of the photodetectors require fast response speed, high signal-to-noise ratio, low energy consumption and low fabrication cost. Unfortunately, most reported β-Ga₂O₃-based photodetectors usually possess a relatively long response time. In addition, the β-Ga₂O₃ photodetectors based on bulk, the individual 1D nanostructure, and the film often suffer from the high cost, the low repeatability, and the relatively large dark current, respectively. In this paper, a Au/β-Ga₂O₃ nanowires array film vertical Schottky photodiode is successfully fabricated by a simple thermal partial oxidation process. The device exhibits a very low dark current of 10 pA at −30 V with a sharp cutoff at 270 nm. More interestingly, the 90–10% decay time of our device is only around 64 μs, which is much quicker than any other previously reported β-Ga₂O₃-based photodetectors. Besides, the self-powering, the excellent stability and the good reproducibility of Au/β-Ga₂O₃ nanowires array film photodetector are helpful to its commercialization and practical applications.