Pronounced effects of argon plasma etching on photoluminescence and Schottky contact properties of Pt/ZnO nanorods

Vertically well-aligned ZnO nanorods (NRs) with good crystallization quality and obvious UV photoluminescence (PL) characteristics were grown by hydrothermal method and Ar plasma etching. Schottky diodes were made by evaporating Pt dots on these ZnO NRs. The effects of Ar plasma etching on the PL and Schottky properties of the prepared ZnO NRs were investigated. Compared with the as-grown ZnO NRs, the UV and visible peak area ratio in the PL spectra increased from 3.8 to 840 with decreased reverse current from 10−3 A to 10−6 A, and increased current on/off ratio of the ZnO NRs Schottky diode from 1 to 102 after 60-min Ar plasma etching. The results suggest that the low-energy Ar plasma etching is an effective method to promote the performance of the Pt/ZnO NRs diode by improving the crystallization quality of the ZnO NRs.