Tungsten Oxide (WO<sub>3</sub>) Films Prepared by Sol-Gel Spin-Coating Technique

Abstract

Tungsten oxide (WO 3 ) is a transition metal oxide with a wide range of applications such as displays, rear-view mirrors, electrochromic (EC) smart windows and gas sensors. Many techniques were adopted for the fabrication of WO 3 , namely magnetron sputtering, spray pyrolysis and sol-gel synthesis techniques. In this work, WO 3 films were deposited on indium tin oxide (ITO) coated glasses by sol-gel spin-coating method. The film thickness was varied by depositing different number of layers. The WO 3 film thickness and optical transmittance were determined using step profilometer and ultraviolet-visible (UV-Vis) spectrophotometer, respectively. WO 3 film thicknesses increased from 38 nm to 606 nmwith increasing number of deposited layers.The optical transmittance of the WO 3 films in visible range decreased with increasing film thickness. The optical transmittance were at least 70 % up to 10 deposited layers.WO 3 is a promising EC material in the application ofEC devices (ECDs).The application of WO 3 in the EC devices will be discussed.