Influence of Aging, Poisoning and Residual Charges on the Gasochromic Behavior of WO3 Thin Films

Abstract

Thin films of WO3 were deposited in a mixed atmosphere of O2 and Ar gas from a high purity target of 99.99 % tungsten using reactive DC-sputtering technique. Pt catalyst was sputtered on top of the WO3 films from a high purity target of 99.99 % platinum in Ar atmosphere. Coloration takes place in hydrogen gas and bleaching in oxygen gas. During the  Coloration/bleaching process several optical and electrical parameters were determined. The influence of the aging time and poisoning in air was investigated, and the residual charges resulting from the coloring/bleaching processes were discussed. It was found that gasochromic coloration velocity decreases with increasing aging time.