Microstructure and properties of indium tin oxide films produced by electrostatic spray assisted vapour deposition process

Good quality indium tin oxide (ITO) films were successfully deposited on to glass substrates in open atmosphere employing the novel one-step electrostatic spray assisted vapour deposition process. The effect of process parameters such as temperature and deposition time on the microstructure, electrical and optical properties of the ITO films was analysed. A sheet resistance in the range of 50 Ω □−1 and an optical transparency >80% were achieved at a substrate temperature of 500 °C. The X-ray diffraction (XRD) pattern indicates polycrystallinity with grain orientations predominantly along (2 2 2) and (4 0 0) directions with average crystallite size ranging between 15 and 55 nm in the temperature range 300–550 °C. Scanning electron microscopy (SEM) showed spherical grain growth with sizes ranging between 250 and 850 nm and atomic force microscopy (AFM) indicated the ITO films produced at higher temperatures have reduced surface roughness.