Studies and correlation among the structural, optical and electrical parameters of spray-deposited tin oxide (SnO2) thin films with different substrate temperatures

Thin films of tin oxide (SnO2) have been grown by using a simple and economical spray pyrolysis technique. The deposition temperature was optimized to 450 degrees C, while the concentration and quantity of the solution were kept fixed at 2 M and 20 ml, respectively. X-ray diffraction patterns (XRD) studies reveal that the material deposited is polycrystalline SnO2 having primitive tetragonal structure. The lattice parameters, grain size, microstrain and dislocation densities were calculated and correlated with the substrate temperature. The transmission spectra showed a sharp decrease in transmission at the absorption edge and a good form of interference pattern. The figure of merit has been calculated from transmission spectra. Low sheet resistance similar to 16.03 Omega/sq cm and high visible transmission (similar to 86%) were obtained when the films were deposited at the substrate temperature of 450 degrees C. From electrical measurements, the resistivity was found to be 11.5 x 10(-4) Omega cm, while the carrier concentration was calculated to be 8.81 x 10(21) cm(-3). (C) 2008 Elsevier B.V. All rights reserved.