Effect of substrate temperature on structural, optical and porosity properties of SnO2 thin films prepared by atmospheric pressure chemical vapor deposition

Tin Oxide (SnO2) thin films were prepared from SnCl4 center dot 5H(2)O precursors by atmospheric pressure chemical vapor deposition method at 300, 400 and 500 degrees C. The thin films were characterized by different methods such as X-ray diffraction spectroscopy, scanning electron microscopy and UV-vis spectroscopy. The average crystalline size was obtained using Debye-Sherer equation and the optical band gap was calculated using the absorption coefficients. The results of X-ray diffraction showed that with the increase of the substrate temperature the size of grains increased and the optical band gap decreased. The scanning electron microscopy investigation showed that the porosity and the grain size increased with increasing the substrate temperature and the sample prepared at 500 degrees C had a proper porosity character. The result of UV-vis spectroscopy showed that with the increase of the substrate temperatures, the transmission coefficient decreased, the absorption threshold increased and the optical gap decreased.