Temperature-dependent photoluminescence and XPS study of ZnO nanowires grown on flexible Zn foil via thermal oxidation

ZnO nanowires (NWs) were directly grown on ductile zinc foil by thermal oxidation at 500 °C. The highly crystalline ZnO NWs exhibited bidirectional growth preferentially oriented in the [101] orientation. The ZnO NWs were highly resistant to hydroxyl groups and water compared with Zn foil that was oxidized naturally. The narrow excitonic photoluminescence (PL) peak combined with strongly suppressed visible emission demonstrated the high optical quality of the NWs. The binding energies of the donor bands and an acceptor band were obtained through temperature-dependent PL analysis. The NWs would be suitable for flexible planar UV device applications.