Ultraviolet-light emission enhancement and morphology stability for ZnO:Ga nanorod array treated by hydrogen plasma

Vertically aligned and highly uniform ZnO:Ga (1 mol%) nanorod array was fabricated by hydrothermal reaction method and then treated by hydrogen plasma. The results show hydrogen plasma treatment could drastically enhance ultraviolet light emission of ZnO:Ga nanorod arrays with maintaining their morphology, which is extremely important for X-ray imaging with high spatial resolution. Under the excitations of 266 nm laser and Xray, a red-shift of ultraviolet light emission was observed and confirmed to be the internal absorption of ZnO:Ga. A visible light emission in X-ray excited luminescence spectrum revealed that the diffusion of hydrogen in the array had a limited penetration depth. Furthermore, the decay time of the ultraviolet light emission was measured to be less than 1.0 ns. The present work shows the hydrogen plasma treated ZnO:Ga nanorod array can be used as a potential scintillator for the ultrafast and high-spatial-resolution X-ray imaging detectors.