Gas sensing selectivity of oxygen-regulated SnO2 films with different microstructure and texture

Abstract The selectivity of gas sensing materials is increasingly important for their applications. The oxygen-regulated SnO 2 films with (110) and (101) preferred orientation were obtained through magnetron sputtering, followed by annealing treatment. Their micro-structure, surface morphology and gas response were investigated by advanced structural characterization and property measurement. The results showed that the as-prepared (110)-oriented SnO 2 film was oxygen-rich and had more adsorption sites while the as-prepared (101)-oriented SnO 2 film was oxygen-poor and more sensitive to de-oxidation. H 2 gas sensitivity, response speed, selectivity between H 2 and CO of the (110)-orientated SnO 2 film was superior to that of the (101)-orientated SnO 2 film. After treated at high temperature and high vacuum, the reduction of gas-sensing properties of the annealed (110) SnO 2 film was much more than that of the annealed (101) SnO 2 film. The lattice oxygen was responsible for the difference in gas-sensing response between (110) and (101)-oriented SnO 2 films under oxygen regulation. This work indicated the gas-sensing selectivity of the different crystal planes in SnO 2 film, providing a significant reference for design and extension of the related materials.