Synthesis, characterization and gas-sensing properties of SILAR deposited ZnO-CdO nano-composite thin film

The deposition of ZnO-CdO thin films are carried out using successive ionic layer adsorption and reaction (SILAR) method at room temperature. The deposited ZnO-CdO thin films have been characterized using FT-Raman spectroscopy, scanning electron microscopy, UV-vis spectrophotometer, two point probe resistivity method, and contact angle mode. Raman spectroscopy show various peaks from the as deposited films which disappeared after annealing. The SEM reveals the morphology of the films nanosized smooth interlocked sheets all over the surface. The bandgap value of 3.8 eV is observed for as deposited but decreased to 2.9 eV after annealing. Activation energies of 0.43 and 0.11 eV are estimated for the as deposited film and annealed film, respectively. The Gas response of the ZnO-CdO composite film shows maximum (about 50%) at 623 K upon exposure to 780 ppm of LPG. (C) 2014 Elsevier B.V. All rights reserved.