The influence of thermal processing on microstructure of sol-gel-derived SrSnO3 thin films

Polycrystalline SrSnO3 thin films were fabricated using the aqueous sol-gel process and deposited on the single crystal sapphire (R-Al2O3 and C-Al2O3) and Si substrates by spin coating technique. Two different processing of thermal treatment was explored to produce SrSnO3 thin films of different porosity. The XRD analysis showed that polycrystalline films with preferential growth of SrSnO3 (200) plane were obtained on C-Al2O3 substrates, while films deposited on R-Al2O3 demonstrated a random polycrystalline growth. FE-SEM analysis revealed that the higher porosity of SrSnO3 films can be achieved by introducing additional thermal treatment step during the deposition procedure. The UV-Vis reflectance spectroscopy was used to study the effect of porosity on optical properties of the films.