The effects of gas exposure and UV illumination on field emission from individual ZnO nanowires

Abstract

Individual ZnO nanowires grown on a Pt tip were exposed to O2 and H2 in the course of field emission. O2 exposure was found to suppress field emission, while H2 reduced the turn-on voltage and increased the emission current. Upon UV (250-400 nm) illumination, the emission current increased almost immediately by about two orders of magnitude, but takes a much longer period, depending on the vacuum level, to fall to its original value following illumination. These phenomena can be accounted for with reference to mechanisms responsible for the sensitivity of metal oxides to oxidizing and reducing gases. © 2007 IOP Publishing Ltd.