Influence of Gas Flow on Structural and Optical Properties of ZnO Submicron Particles Grown on Au Nano Thin Films by Vapor Phase Transport

ZnO submicron particles were grown on Au-catalyzed Si substrates using a vapor phase transport (VPT) growth process under different mixture gas ratios at a growth temperature of 900 degrees C. The structural and optical properties of the ZnO submicron particles were investigated using field-emission scanning electron microscopy (FE-SEM), x-ray diffraction (XRD), and photoluminescence (PL). The ZnO submicron particles were clustered for the O-2/Ar mixture gas ratios (%) higher than 10%, which was largely determined by the ambient gas. In particular, for an O-2/Ar mixture gas ratios of 30%, ZnO submicron particles with diameters between 125 - 500 nm were observed; in addition, the narrowest XRD full width at half maximum (FWHM) values and PL spectra with 0.121 degrees and 92 meV were reported. The structural and optical properties of the ZnO submicron particles improved as the O-2/Ar mixture gas ratio was increased, as observed from the XRD and PL spectra results.