Mn doping effect on the structural properties of ZnO-nanostructured films deposited by the ultrasonic spray pyrolysis method

Abstract

Mn-doped ZnO thin films with different percentages of Mn content (0, 1, 3 and 5 at%) and substrate temperature of 350 °C, were deposited by a simple ultrasonic spray pyrolysis method under atmospheric pressure. The chemical compositions and surface morphologies were examined by dispersive x-ray spectroscopy and scanning electron microscopy micrographs. We have studied the structural and optical properties by using x-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy and ultra-violet visible near-infrared spectroscopy. The lattice parameters calculated for the Mn-doped ZnO from XRD pattern were found to be slightly larger than those of the undoped ZnO, which indicate substitution of Mn in the ZnO lattice. Compared with the Raman spectra for ZnO pure films, the Mn-doping effect on the spectra is revealed by the presence of an additional peak about 524 cm−1 due to Mn incorporation. With increasing Mn doping the optical band gap increases indicating the Burstein–Moss effect.