Synthesis and characterization of nanocrystalline CdZnO thin films prepared by sol-gel dip-coating process

Nanocrystalline CdxZn1-xO thin films with different Cd volume ratios in solution (x = 0, 0.25, 0.50, 0.75 and 1) have been deposited on glass substrate by sol-gel dip-coating method. The as-deposited films were subjected to drying and annealing temperatures of 275 degrees C and 450 degrees C in air, respectively. The prepared films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-vis spectroscopy and dc-electrical measurements. The results show that the samples are polycrystalline and the crystallinity of the films enhanced with x. The average grain size is in the range of 20-53 nm. The atomic percent of Cd:Zn was found to be 9.50: 1.04, 6.20:3.77 and 4.42:6.61 for x=0.75, 0.50 and 0.25, respectively. It was observed that the transmittance and the band gap decreased as x increased. All the films exhibit n-type electrical conductivity. The resistivity (rho) and mobility (mu) are in the range of 3.3x10(2)-3.4x10(-3) Omega cm, and 1.5-45 cm(2) V-1 s(-1) respectively. The electron density lies between 1.26x10(16) and 0.2x10(20) cm(-3). Crown Copyright (C) 2011 Published by Elsevier B. V. All rights reserved.