Highly transparent amorphous tin oxide thin films by sol-gel spin coating technique

This paper reports the preparation and characterization of amorphous tin oxide thin films by sol-gel spin coating technique. The structural properties were analyzed by using XRD, FESEM and EDAX measurements. XRD analysis reveals that the as prepared tin oxide thin films were amorphous in nature. No crystalline peaks corresponding to the tetragonal rutile structure of tin oxide were present in it. FESEM analysis reveals that the particles were uniformly distributed in the tin oxide thin films. EDAX analysis shows that the as prepared tin oxide thin films contain tin and oxygen. Optical study was done by using UV-Vis Spectrophotometer and Photoluminescence spectroscopy. Transmittance spectra show that as prepared tin oxide thin film has highly transparent up to 85%. The optical band gap was calculated using Tauc plot and the value of optical band gap was obtained as 3.64eV. PL study shows an intense and broad blue asymmetric emission band centered at 389nm. Electrical study was done by using Keithley's four probe techniques. The resistivity was obtained as 1.21 × 10−3Ωm. The Figure of Merit value was calculated using Haacke formula and the obtained value was 2.2139x105Ω-1. Thus good quality amorphous tin oxide thin films were successfully prepared by sol-gel spin coating technique.