OPTIMIZNG PROCESS PARAMETERS AND CHARACTERIZATION OF NANOSTRUCTURED INDIUM TINOXIDE (ITO) THIN FILMS VIA SOLGEL SPIN COATING TECHNIQUE

Highly transparent indium tin oxide thin films (ITO) were prepared using sol-gel spin coating technique. Process parameters such as annealing temperature, heating rate and thickness of coatings were optimized. The films were first dried at 150°C and then annealed in air in the temperature range of 300-600°C. Structural, morphological, electrical and optical properties of the resulting ITO thin films with different processing parameters were investigated by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), four-point probe and UV-Vis spectroscopy, respectively. XRD analysis confirmed the presence of InC3 bixbyite as the only crystalline phase. FESEM micrographs show that all of the samples were crystalline with grain sizes in the range of 17-40 nm depending on the annealing conditions. UV-Vis spectra shows that the films prepared at optimum conditions are highly transparent in the visible region with a transmittance of more than 90%. Under optimum conditions, resistivity lower than 90x10 S.cm and transmittance of more than 95% in the visible range were obtained for ITO thin films at thickness of about 500 nm and annealed at 600°C.

کلیدواژه ها:

Indium tin oxide (ITO) ، Sol-gel method ، Spin coating ، Nanostructured thin film