Influence of annealing temperature on structural properties of ITO thin-films on graphite substrate

In various industrial applications including thin-film solar cells indium tin oxide (ITO) is widely used. In this research work highly electrically conductive Tin-doped indium oxide (ITO) was deposited on graphite substrate using e-beam evaporator at substrate temperature 300 °C and 400 °C. Thermal treatment of the deposited ITO thin film was further done with the temperature values up to 900 °C. ITO nanostructures were found to be grown at 400 °C with diameters of 30-35 nm and remained stable even at 800 °C. At 900 °C, the ITO characteristics were observed to change. The In and Sn concentrations were decreased, while carbon (C) and oxygen (O2) were found to be increased at 900 °C. The increase in O2 was observed to be 54% while the concentration of C increased from 15% to 45%. Optical and FE-SEM characterization were done to study the morphology and surface roughness of ITO thin-films. TEM and XRD was used to study the crystallinity of these ITO nanostructures. Similarly, X-Ray photoelectron spectroscopy (XPS) was used to measure the components and the chemical state. Depth profiling was measured using secondary-ion-mass-spectroscopy (SIMS) of these thin films on graphite substrate at different annealed temperatures upto 900 °C.