Structural and Optical Properties of Compact SnO2 Thin Films by Sol Gel Dip Coating

Compact nanocrystalline tin oxide (SnO2) thin films were prepared by sol gel dip coating technique. The effect of the number of coatings and aging time on the microstructure, optical and photoluminescence properties were studied. The results showed a photoluminescence peak at 410 nm, whose intensity decreased with increasing number of coatings. The optical properties of the films were analyzed by UV-visible absorption spectroscopy and the result showed optical band gap variation in the range of 3.55 to 3.75 eV as an effect of preparation parameters. The tetragonal structural behavior of the compact thin films was observed from X-ray diffraction pattern as an effect of annealing. It was also observed that, the morphology of compact SnO2 thin films was highly dependent on the thickness, aging time, as determined by scanning electron microscopy. The prepared compact films may have potential applications for blocking layer in dye sensitized solar cell.