Enhanced band-gap emission in ZnO Nanocaves by two-step thermal oxidation Zn film

ZnO Nanocaves are grown on p-type silicon substrate by two-step thermal oxidation Zn films. The samples are characterized by X-ray diffraction, scanning electron microcopy and photoluminescence. We observe that the band-gap emission can be great improvement while the defects emission is suppressed to noise level after the ZnO Nanocaves annealed in nitrogen ambient at 600 degrees C for 1 h. The improvement of crystalline quality. Au nanoparticles and ZnO Nanocaves layer should responsible for the giant enhancement of band-gap emission and the disappearance of defects emission. The results indicate that the ZnO Nanocaves have great potential applications in optoelectronics such as laser emitting devices, laser diodes and spintronics. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.