Studies on the structural and electrical properties of F-doped SnO 2 film prepared by APCVD

Abstract

Fluorine-doped tin oxide films (SnO 2:F, FTO) were deposited by atmosphere pressure chemical vapor deposition (APCVD) on Na–Ca–Si glass coated with a diffusion barrier layer of SiO x C y . The effects of post-heating time at 700 °C on the structural and electrical properties of SnO 2:F films were investigated. The results showed that SnO 2:F films were polycrystalline with tetragonal SnO 2 structure, SnO phase was present in SnO 2 film, and abnormal grain growth was observed. The element distribution in the film depth was measured with X-ray photoelectron spectroscopy (XPS) and revealed that when the heating time increased from 202 s to 262 s, the oxygen content in the surface increased from 78.63% to 83.38%. The resistivity increased from 3.13 × 10 −4 for as-deposited films to 4.73 × 10 −4 Ω cm when post-heated for 262 s. Hall mobility is limited by the ionized impurity scattering rather than the grain boundary scattering.