Synthesis and photoluminescence properties of ZnO nanowires and nanorods by thermal oxidation of Zn precursors

A newly developed route has been used to fabricate single-crystalline thin ZnO nanowires (T-ZNWs) and ZnO nanorods (ZNRs) by simple thermal oxidation of wirelike Zn precursors under 5 Pa at 400 °C and 600 °C, respectively. The T-ZNWs grow along the [21¯1¯0] direction via a “self-catalytic liquid–solid” process, while the ZNRs grow along the [0001] direction following a vapor–solid mechanism. Photoluminescence (PL) spectra were used to investigate the optical properties of the oxidized samples. The products consisting of the T-ZNWs and thick trunks show a strong green emission related to the oxygen vacancies, while the ZNRs oxidized at higher temperature exhibit strong ultraviolet emission with negligibly weak green emissions, indicating the high optical quality of ZNRs.