Conducting antimony-doped tin oxide films derived from stannous oxalate by aqueous sol-gel method

摘要

Nanocrystalline SnO_2:Sb films were prepared by a sol-gel route using C_6H_8O_7-triethanolamine (TEA) mixing aqueous solution with pH 6.5-7.0. Stannous oxalate and antimony trichloride were used as tin and antimony sources. IR, XRD FESEM, FETEM, UV-vis and four-point probe measurement were used to characterize sol-gel chemistry, structure, morphologies, optical and electrical properties. Mechanism of sol-gel reaction illuminated that existence of TEA supplied large numbers of active tin hydrate and ionized state carboxyl groups for tin and antimony chelation through the amido association with the ionized H~+ on -COOH of H_3L and H_2C_2O_4. The 6 at.% Sb-doped films with film thickness of 600 nm had sheet resistance as low as 42.85^2/ when annealed at 450 ℃ for 10min. Annealing temperature intensively altered sheet resistance and optimum was in the range of 450-500 ℃. The longer annealing time caused Sb volatilization which led to the optimum doping level shifted from 6 to 12 at.%.