Preparation of β-Ga2O3 nanostructured films by thermal oxidation of GaAs substrate

Abstract The β-Ga2O3 nanostructures of one-dimensional (1D) nanowires (NWs) and bulk films were prepared by thermal oxidation (TO) of GaAs substrate. The growth mechanisms of β-Ga2O3 are discussed in detail. The formation of these NW structures is closely linked to the process of oxygen-free annealing. The two kinds of nanostructured films have distinct structure differences while the same crystal plane orientation. Compared with bulk films, the NW films show higher donor-acceptor pair-induced blue emission. A p-GaAs/β‐Ga2O3 NWs heterojunction was fabricated with a turn-on voltage of 1.3 V matching well with simulation results. The proposed method can flexibly and catalyst-free prepare high-quality, high surface-to-volume ratio and uniform β-Ga2O3 NW films, which is promising for optoelectronics and gas sensing.