Effects of surface modification of the individual ZnO nanowire with oxygen plasma treatment

This study examined the effects of an oxygen plasma treatment on the properties of ZnO nanowires with diameters of 80 nm using a single nanowire field effect transistor. After the oxygen plasma treatment, the carrier concentration and mobility of individual ZnO nanowires decreased with a substantial positive shift in the threshold voltage. The shifting was accounted to the surface modification, resulted to the improved gas sensitivity under hydrogen gas exposure and an enhanced photocurrent response time in ultraviolet illumination. The plausible surface mechanisms responsible for these significant changes after the surface modification were suggested by considering the surface analysis and electrical transport mechanism.