Preparation of ITO thin film by dual-spray deposition of aerosol droplets and improvement of electrical property

Abstract

ITO (indium tin oxide) is one of the most widely used TCO (transparent conducting oxide) because of low resistivity and high transmittance. To decrease the amount of ITO usage, silver and purified SWNT were added to the ITO in this study. However, the chemical reaction between $AgNO_3$ and Cl ion in $InCl_3$ and $SnCl_2$ prohibits to use $AgNO_3$ are an additive. Non-uniform dispersion of SWNT in the ITO precursor solution is also another difficulty. To solve these problems, dual spray deposition technique is proposed. The resistivity of thin film depends on the substrate temperature and concentration of Ag and SWNT. This is because the Ag and SWNT additive and temperature alter the grain size and density of thin film. ITO-Ag thin film deposited at the substrate temperature of 400℃ with the silver concentration of 9.1 at.% had the lowest resistivity of $2.4×10^{-4}Ω\cdot cm$. Furthermore, the lowest resistivity of $2.6×10^{-4}Ω\cdot cm$ is observed when the ITO-SWNT thin film was prepared at 400℃ with 0.72 wt.%. The transmittance in the visible wavelength region did not have remarkable change when the concentration of Ag and SWNT are increased. The transmittance depended on the film thickness more than the concentration of additives.