Adsorption and desorption properties on the fluorine-doped tin oxide film surface on a glass substrate under UV light irradiation in vacuum

Various functional metal-oxide coatings on glass substrate have the possibility to be used for many applications in these days. For keeping the high performance of these applications, it is very important to understand the adsorption property on those coating surfaces. However, there are few reports about such properties of metal-oxide film surface in vacuum state, especially the carbon adsorption property on fluorine-doped tin oxide (SnO2:F) film in vacuum. In this study, we have investigated the chemical state on SnO2:F film in vacuum with XPS analysis. From the results of the SnO2:F film surface analysis, the adsorbed carbon (C1s orbit) on the SnO2:F film surface and the adsorbed carbon dependence of heat treatment in vacuum were observed. Also, it was found that the adsorbed carbon distribution on the SnO2:F film existed after the heat treatment at low temperature in vacuum, uniformly spread in large area with UV light irradiation. Besides, the influence of UV light irradiation with respect to the carbon contents in the SnO2:F film was observed by SIMS analysis. As the result, it was implied that the carbon state in the SnO2:F film remained unchanged under UV light irradiation and the carbon adsorption and desorption occurred only on the surface of the SnO2:F film.