Highly c-Axis Oriented Growth and Optical Characterization of ZnO Pore-Like Structures Surrounded by Craters via Pulsed Laser Deposition

Abstract

This research deals with the deposition and characterization of ZnO nanostructures by the pulsed laser deposition technique at various ambient pressures of oxygen on a silicon substrate at 600 ∘C temperature. X-ray diffraction study shows that the ZnO nanostructure is single crystal in nature and has strong c-axis orientation. The field emission scanning electron microscopic image shows that the formation of pores within the craters is highly sensitive to the oxygen pressure. The atomic force microscopy image reveals the reduction in surface roughness of the nanostructure indicating transformation of pores to particles. A near-band-edge emission peak along with the defect peaks arising from oxygen defects and zinc interstitials are observed in the photoluminescence spectra. The defect related emission due to O 2 vacancy decreases with increasing O 2 pressure due to more incorporation of O 2 during pulsed laser deposition.