Achieving fast oxygen response in individual β-Ga2O3 nanowires by ultraviolet illumination

The authors report a route to realize very quick oxygen response and demonstrate it by using individual β-Ga2O3 nanowires. The current across the nanowire is at a low level and varies slightly with changing the oxygen pressure. In contrast, under 254nm ultraviolet illumination, the current increases rapidly to a value that reflects the level of the oxygen pressure around the nanowire. The illumination gives rise to the oxygen sensing. This optically driven oxygen sensing is the origin of the fast response. The results demonstrate a promising approach to realize fast-response gas sensors.