Investigation on tin concentration dependence of solution processed indium oxide thin film

Abstract

Indium tin oxide (ITO) thin films have been prepared by spray pyrolysis using a very low concentration of indium precursor. The spray process parameter like the concentration of SnO precursor in spray solution,  have been optimized for obtaining optically transparent, structure and device-quality ITO films.

The material properties are reported by studying the structural and optical properties of the ITO films prepared at a relatively lower temperature of 574K. The surface morphology has been studied by atomic force microscopy it was found ITO films have nanostructured. The grain size and the roughness of the films doping concentration 2%, 4% and 6% was (76, 87 and 127)nm and (0.969, 2.56 and 1.61)nm respectively. The concentration rate 2% produces an overall shift to lower photon energies of the optical constant spectra and the optical transmission of greater than 85%, which is related to the increase in electrical resistivity. Characterization of ITO on glass and silicon has shown that increasing the concentration rate will increase in the optical band gap of the ITO films. Samples deposited at doping concentration 2%, 4% and 6% the optical gaps of 3.74 eV, 3.9 eV and 3.73 eV respectively.

Keyword: Indium tin oxide, spray pyrolysis, optical properties and nanostructure properties