Influence of Substrate Temperature on Structural, Electrical and Optical Properties of Nanostructured SnO2 thin Films Deposited by Spray Pyrolysis Technique

Abstract

Received: 15/Feb/2019, Accepted: 12/Mar/2019, Online: 30/Apr/2019 Abstract—SnO2 nanostructured thin films were deposited on ultrasonically cleaned glass substrates at different substrate temperatures using the spray pyrolysis technique. The influence of substrate temperature on structural, morphological, electrical and optical properties of thin films have been investigated by X-ray diffraction (XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy (EDAX), two probe method and UV-Vis spectroscopy respectively. It was found that the deposited thin films were showing a tetragonal structure with a preferred orientation along (200) direction. Scanning electron microscopy results have shown that the substrate temperature influenced the growth mechanism of the SnO2 thin films. Optical properties of thin films were analyzed by UV-Vis spectrophotometer. Optical band gap values were determined using Tauc extrapolation at different substrate temperatures. As the substrate temperature increased from 350 o C to 450 o C, optical band gap was found to increase from 3.14 eV to 3.67 eV. The figure of merit has been calculated from transmission spectra and the electrical properties are analysed and discussed.