Effect of the Substrate Nature on Electron Transport in Ga Doped ZnO Thin Films Grown by RF Sputtering

The influence of substrate nature on structure and the electrical properties of 2% Ga-doped ZnO thin films deposited on different substrates by rf magnetron sputtering is presented. XRD, AFM and XPS studies evidenced that thin films have a highly textured hexagonal structure, with a surface morphology dependent on substrate nature. The conduction mechanism is discussed in terms of grain boundary (GB) and nearest-neighbor hopping (NNH) conduction models. The decrease in the potential barrier height is considered to be caused by the increase in the crystallite size as a consequence of charge carrier scattering diminution at the grain boundaries. Surface trap density was found to be influenced by the substrate nature, the smallest value of being obtained for the SiO2/Si substrate. (c) 2017 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of 11th International Conference on Physics of Advanced Materials (ICPAM-11).