Study on field emission and photoluminescence properties of ZnO/graphene hybrids grown on Si substrates

Zinc oxide/graphene (ZnO/G) hybrids are prepared on n-Si (1 0 0) substrates by electrophoretic deposition and magnetron sputtering technique. The crystal structure, morphology and photoluminescence (PL) properties of the ZnO/G hybrids are analyzed via X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and fluorescence-phosphorescence spectrometer, respectively. The results indicate that the crystal quality of ZnO nanostructure deteriorates after depositing graphene buffer layer. Whereas many three dimensional stacking blowballs form in the ZnO/G hybrid, creating a larger surface area than that of ZnO nanostructure. The photoluminescence (PL) spectrum of the ZnO/G hybrid contains multi-peaks, which are consistent with ZnO nanostructure except for two new peaks at 390 and 618 nm. In addition, field emission measurement reveals that E-to and E-thr decrease from 8.01V mu m(-1) and 14.90V mu m(-1) of the ZnO nanostructure to 2.72 V mu m(-1) and 7.70 V mu m(-1) of the ZnO/G hybrid. ZnO/G hybrid is characteristic of having excellent emitting behavior suitable for application in field emission technology. (C) 2012 Elsevier B.V. All rights reserved.