Wet-Chemical Synthesis of ZnO Nanowires on Low-Temperature Photo-Activated ZnO-rGO Composite Thin Film with Enhanced Photoconduction

Abstract

A homogeneous dispersion of graphene oxide (GO) and zinc acetate was dip-coated and subsequently photo-annealed by deep UV irradiation to form ZnO-rGO (DUV) nanocomposite thin film. ZnO nanowires were then grown by wet-chemical synthesis on the ZnO-rGO (DUV) thin film. For comparison, ZnO nanowires were also grown on bare ZnO and ZnO-rGO (HT) thin films thermally annealed at 500°C. X-ray diffraction and Raman spectroscopy of ZnO-rGO (DUV) thin film revealed crystallization of ZnO and reduction of GO. The photoluminescence spectra of ZnO nanowires grown on ZnO-rGO (DUV) thin film showed high crystallinity. The current–voltage characteristics of ZnO nanowires grown on ZnO-rGO (DUV) thin film in dark and under UV showed a 15-fold increase in photocurrent as compared to ZnO nanowires grown on ZnO and ZnO-rGO (HT) thin films. The low-temperature photo-activated ZnO-rGO thin films can be used as a template to grow one-dimensional ZnO nanowires with improved structural and optical properties and can pave the way for high-performance flexible device fabrication.