Electrical, structural and optical properties of SnO2:F thin films: Effect of the substrate temperature

SnO2:F thin films have been deposited from stannic chloride solution by simple and cost effective chemical spray pyrolysis technique onto glass substrates at different substrate temperatures. The as-deposited films were characterized by X-ray diffraction (XRD), SEM, optical and electrical characterization techniques. XRD analysis showed that, at lower substrate temperature; amorphous films have been obtained, while at higher temperatures (T>450 degrees C):crystalline SnO2:F films with preferential growth along (2 0 0) plane have been observed. The average transmission in the visible region has been found to vary from 60% to 87% depending upon the substrate temperature. In the visible region of the spectrum, the transmission is very high (high enough to observe interference). For films prepared at 475 degrees C, relatively higher transmittance of about 87% at 850 nm has been observed. A thickness was found to vary from 440 nm to 740 nm with substrate temperature. The direct optical band gap energy for the SnO2:F thin film is found to be 4.15 eV. The films deposited at 475 degrees C substrate temperature were found to have relatively lower resistivity of 3.91 x 10(-4) Omega cm. Hall Effect studies reveal that the films exhibit n-type conductivity. (C) 2009 Elsevier B.V. All rights reserved.