Effect of growth temperature on the morphology and bonded states of SnO ₂ nanobaskets

The nanobaskets of SnO ₂ were grown on in-house fabricated anodized aluminum oxide pores of 80 nm diameter using plasma enhanced chemical vapor deposition at an RF power of 60 W. Hydrated stannic chloride was used as a precursor and O ₂ (20 sccm) as a reactant gas. The deposition was carried out from 350 to 500 °C at a pressure of 0.2 Torr for 15 min each. Deposition at 450 °C results in highly crystalline film with basket like (nanosized) structure. Further increase in the growth temperature (500 °C) results in the deterioration of the basket like structure and collapse of the alumina pores. The grown film is of tetragonal rutile structure grown along the [1 1 0] direction. The change in the film composition and bonded states with growth temperature was evident by the changes in the photoelectron peak intensities of the various constituents. In case of the film grown at 450 °C, Sn 3d _5/2 is found built up of Sn ⁴⁺ and O-Sn ⁴⁺ and the peaks corresponding to Sn ²⁺ and O-Sn ²⁺ were not detected.