Mg doping effect on the microstructural and optical properties of ZnO nanocrystalline films

摘要

Transparent Zn_(1-x)Mg_xO (x = 0.01, 0.03 and 0.05) nanocrystalline films were prepared by sol-gel method followed by thermal annealing treatment of 700°C. Mg doping effect on the microstructural and optical properties of the Zn_(1-x)Mg_xO films were investigated. From SEM images of all films, mean sizes of uniform spherical grains decreased progressively. Pure wurtzite structure was obtained from the results of XRD. Grain sizes increased from 34.7 nm for x = 0.01, 37.9 nm for x = 0.03 to 42.1 nm for x = 0.05 deduced from the XRD patterns. The Photoluminescence spectra of the films show a strong ultraviolet emission and a weak visible light emission peak. The enhancement of ultraviolet emission and reduction of visible emission is observed due to the increase of Mg doping concentration and the corresponding decrease of oxygen vacancy defects.