Studies on undoped SnO2 thin film deposited by chemical reactive evaporation method

Transparent conducting undoped tin oxide thin film were prepared by chemical reactive evaporation method at various substrate temperature and post deposition heating for 30 min. Structural, electrical, optical and mechanical properties were studied. The film showed direct band gap in the range of 3.12–3.28 eV and the refractive index from 1.785 to 1.921. The minimum sheet resistance of ∼243 Ω was obtained at 450 °C. All the film showed high adhesion with highest adhesion of the film deposited at 450 °C. Post deposition heating increases the adhesion. The post deposition heated films showed decrease in transmittance and increase in band gap, refractive index and sheet resistance. The chemical reactive evaporation method is a very cost effective method for obtaining good quality undoped tin oxide thin films of lower resistance.