Growth and characterization of molybdenum doped ZnO thin films by spray pyrolysis

Undoped and molybdenum doped zinc oxide (MZO) thin films were deposited on the glass substrate at a substrate temperature of 623 K by spray pyrolysis method. The effect of molybdenum (Mo) dopant concentration (0-4 at%) on the structural, morphological, optical and electrical properties of n-type MZO films was studied. The X-ray diffraction (XRD) results confirmed that the MZO thin films were polycrystalline with wurtzite structure. The scanning electron microscopy (SEM) measurements showed that the surface morphology of the films changes with Mo doping. The surface roughness of the films was investigated by atomic force microscopy (AFM). It was observed that the roughness of the films increases with the increase of Mo doping percentage. A blue shift of the optical band gap was observed. Room temperature photoluminescence (PL) measurement of the deposited films indicates the incorporation of Mo in ZnO lattice. The temperature dependence of the electrical conductivity was studied in the range of 300 K-425 K. At 2 at% Mo doping, the films have shown comparatively high electrical conductivity. (C) 2012 Elsevier Ltd. All rights reserved.