Effect of the substrate temperature on the properties of spray-deposited SnO2:F thin films

The effect of the substrate temperature on the properties of spray-deposited SnO2:F thin films is investigated. X-ray diffraction patterns show that the crystallinity of the films is enhanced with the increasing of substrate temperature. Comparing the SEM images, both the particle size and density are increased at a higher deposition temperature. The lowest sheet resistance of 8.43 Omega/a- is obtained at the substrate temperature of 350 A degrees C. In addition, the average optical transmittance of the three films reaches up to 85 % in the visible range. The absorption coefficient is the lowest at 350 A degrees C. The band gap increases from 3.36 to 3.61 eV while the electrical resistivity of SnO2:F thin films decreases from 8.51 x 10(-3) to 9.86 x 10(-4) Omega cm as elevating the substrate temperature from 250 to 350 A degrees C.