Effect of substrate temperature on electrical and optical properties of spray deposited SnO2:Sb thin films

Thin films of similar to 1.2 mum thick antimony doped tin oxide (SnO2:Sb) have been prepared using an economic spray pyrolysis technique from SnCl2 precursor at two different substrate temperatures (T-s), namely 350 C and 400 degreesC. The effect of substrate temperature on the electrical and optical properties is studied and presented in this article. A minimum sheet resistance of 2.17 Omega/square was obtained for the film prepared at 400 C. This minimum sheet resistance observed in the present study is the lowest among the reported values for SnO2:Sb films prepared from SnCl2 precursor. Irrespective of the substrate temperature, the transmittance was found to decrease with the increase in Sb doping concentration. The highest optical transmittance obtained for the films prepared at lower T-s (350 degreesC) is found to decrease from 63 % to a value of 54 % (at 800 nm) for the films prepared at higher T-s (400 degreesC). The calculated IR reflectivity was found to be in the range of 93 -97 % and 94 - 98 % for the films prepared with lower and higher substrate temperatures, respectively. The estimated high IR reflectance of these films suggests that the films are useful in flat plate collectors and in different electrode processes.