Preparation and photoluminescence studies of high-quality AZO thin films grown on Zno buffered Si substrate

Al-doped ZnO (AZO) films were deposited by radio frequency (RF) reactive magnetron sputtering. The effects of buffer layer, annealing temperature and atmosphere on the structure, crystallinity and optical properties of epitaxial AZO films were investigated. The XRD results indicate that AZO thin films deposited on buffer layer has a better c-axis preferentially oriented growth than AZO films without buffer layer, and a better crystal quality can be obtained by an appropriate annealing process. The PL spectra show excellent UV/vis light-emitting characteristics: 387 nm, 424 nm, 463 nm and 506 nm. The intensities of the UV/vis peaks change when AZO films are annealed in oxygen or vacuum at different temperatures. The origin of the UV/vis emissions is discussed and the photoluminescence mechanism of AZO films is suggested. (C) 2015 Elsevier B.V. All rights reserved.