Molybdenum doped tin oxide thin films for self-cleaning applications

摘要

Photo responsive SnO_2 and Mo doped SnO_2 (Mo-SnO_2) thin films have been produced by thermal evaporation technique. Hydrophobic-hydrophilic switching in pure SnO_2 and Mo-SnO_2 films are demonstrated by alternating between ultra-violet (UV) light irradiation and dark storage. Wettability studies reveal that incorporation of Mo on SnO_2 thin film rapidly enhances the switching reversible transition between hydrophobic to hydrophilic in contrast to pure SnO_2 thin film. Thus Mo doping in SnO_2 is effective in boosting the hydrophilicity of SnO_2 film. The difference in behaviour is attributed to the larger number of oxygen vacancies on Mo doping of SnO_2 film which is also evident from the differences in refractive index and optical band gap of the doped and undoped films.