Studies on optical properties of polycrystalline SnO2:Sb thin films prepared using SnCl2 precursor

Optical proper-ties of spray deposited antimony (Sb) doped tin oxide (SnO2) thin films, prepared from SnCl2 precursor, have been studied as a function of antimony doping concentration. The doping concentration was varied from 0-4 wt. % of Sb. All the films were deposited on microscope glass slides at the optimized substrate temperature of 400degrees C. The films are polycrystalline in nature with tetragonal crystal structure. The doped films are degenerate and n-type conducting. The sheet resistance of tin oxide films was found to decrease from 38.22 Omega/square for undoped films to 2.17 Omega/square for antimony doped films. The lowest sheet resistance was achieved for 2 wt. % of Sb doping. To the best of our knowledge, this sheet resistance Value is the lowest reported so far, for Sb doped films prepared from SnCl2 precursor. The transmittance and reflectance spectra for the as-deposited films were recorded in the wavelength range of 300 to 2500 nm. The transmittance of the films was observed to increase from 42 % to 55 % (at 800 nm) on initial addition of Sb and then it is decreased for higher level of antimony doping. This paper investigates the variation of optical and electrical properties of the as-deposited films with Sb doping.