Investigation of the optical property and structure of WO 3 thin films with different sputtering depositions

Abstract

The purpose of this research was to compare the optical properties and structure of tungsten oxide (WO 3 ) thin films that was deposited by different sputtering depositions. WO 3 thin films deposited by two different depositions of direct current (DC) magnetron sputtering and pulsed DC sputtering. A 99.95% WO 3 target was used as the starting material for these depositions. These WO 3 thin films were deposited on the ITO glass, PET and silicon substrate by different ratios of oxygen and argon. A shadow moiré interferometer would be introduced to measure the residual stress for PET substrate.RF magnetron sputtering had the large residual stress than the other's depositions. A Raman spectrum could exhibit the phase of oxidation of WO 3 thin film by different depositions. At the ratio of oxygen and argon was about 1:1, and the WO 3 thin films had the best oxidation. However, it was important at the change of the transmittance (ΔT = T bleached -T colored ) between the coloring and bleaching for the smart window. Therefore, we also found the WO 3 thin films had the large variation of transmittance between the coloring and bleaching at the gas ratios of oxygen and argon of 1:1.