Microstructure and photoluminescence of MoOx decorated ZnO nanorods

Various MoOx decorated ZnO nanorods (ZnO-MoOx) samples were fabricated by physical vapor deposition of MoOx on the surface of ZnO nanorods with varying deposition time and temperature. The microstructure and photoluminescence (PL) of the ZnO-MoOx samples were investigated. It was found that the morphology of the ZnO nanorods is changed from hexagonal prisms to lotus-roots-like shapes by the decoration of MoOx. The lotus-roots-like shapes may be formed by partial melting and evaporating of ZnO-MoOx during the MoOx decoration. This result shows that one can use the thermal instability of a nano-material to obtain an interesting structure, although a thermal instability should often be avoided. The intensity of the ultraviolet and visible light emission the of ZnO nanorods have different dependencies on the MoOx decoration. Although the position of the ultraviolet light emission is not obviously changed by the MoOx decoration, the ultraviolet light emission intensity is greatly weakened. In contrast, the intensity and position of visible light emission is largely changed. The blue shift of the visible light emission might be related to defects introduced by melting of the ZnO nanorods.