The preparation of ITO films via a chemical solution deposition process

Indium-tin-oxide (ITO) films were deposited on substrates of soda lime glass via a dipping coating process from a mixed ethanolic solution of indium nitrate and tin chloride. The conductivity of the ITO films were improved by adding in the bath of active carbon to create a reducing atmosphere during heating. Under such an active carbon process, the optimum conditions of heat-treatment such as atmosphere, soaking temperature and Sn/In ratio for low sheet resistance of ITO film was investigated. The best sheet resistance of ITO films made from this process was 248±28 Ω/□ with Sn/In ratio of 0.08 which was heat-treated at 550 °C for 1 h in vacuum with active carbon. The optical transmittance of the films in the range of 400–800 nm was 80–90%.