Stability of siloxane couplers on pure and fluorine doped SnO2 (110) surface: A first principles study

Siloxane is a favorable candidate as an anchor group that can be used to bind organic molecules to SnO2 surfaces, with a wide range of practical applications. Therefore, adsorption geometries and energies of siloxane coupler on the SnO2 (110) surface have been investigated in this study using quantum-chemical periodic density functional theory (DFT) calculations. We present a comparative study of different siloxane adsorption arrangements on pristine and fluorine doped SnO2 surface. According to the calculations, the surface doping with fluorine leads to stabilization of the siloxane network at the stannic oxide surface. The trend is analyzed in terms of additional charge provided by F impurities to the chemisorbed oxygen atoms thus increasing the ionicity of their bonding. Implications of the current findings for the design of organic-metal oxide interface with better thermo-stability and improved electronic properties are discussed.