Influence of Film Thickness on Electrical and Optical Properties of Vanadium Dioxide Thin Films for Smart Window Coating Application

Abstract

Vanadium dioxide (VO_2) is one of the material for smart window application due to its transition temperature that close to nearest room temperature from 20°C to 30°C. The aim of this research is to study the effect of VO_2 thin films with different spin coating speeds during the deposition process which change the thin film thickness at varies spin coating speed. In this work, quartz substrates were used with 2.0 cm x 2.0 cm dimension. The VO_2 solution was prepared by sol-gel method by mixing the vanadium oxytripropoxide with isopropanol, while VO2 thin film was fabricated using spin coating technique. Five samples were used to characterize the different of spin coating speeds at 1000 rpm, 1250 rpm, 1500 rpm, 1750 rpm and 2000 rpm. The samples of VO_2 thin films produce a different characterization pattern of electrical and optical properties. Samples characterization process were performed using I-V measurements and UV-Visible spectrophotometer. The absorbance and transmittance of VO_2 thin films were checked using UV-Visible spectrophotometer for the optical properties of thin films, while the I-V measurements for the current and voltage of each sample. The result for 1000 rpm sample shows the highest thickness with less grain and high conductivity. As a conclusion, sample with the highest thickness film produced thin film with a good electrical and optical properties.