Ultraviolet photodetector based on vertical β-Ga₂O₃ nanowire array on GaN substrate

Driven by the requirement to ultraviolet detection, β-Ga₂O₃ UV photodetectors have attracted great attention. Using a metal organic chemical vapor deposition (MOCVD) reactor, we grew β-Ga₂O₃ nanowires array on a GaN substrate using Ga as catalyst. The density of the nanowires was optimized employing the substrate patterning technology. A UV detector based on the graphene/β-Ga₂O₃-nanowire-array was realized by micro-fabrication techniques. The device has a wide range of UV response covering UVC-UVA band and the peak response reaches 30.82 mA W⁻¹ at 258 nm corresponding to the band gap of β-Ga₂O₃. The rapid response speed (<1 s) is comparable to that of most reported Ga₂O₃ nanowire ultraviolet photodetectors. (paper)