SIMS and ESCA Studies of Electrochromic WO3 Thin Films

Abstract
The mechanism of electrochromic coloring and bleaching reaction in vacuum-deposited amorphous WO3 thin film was studied, and it was found that the stoichiometry and the hydrogen content in the films did not change during the reaction, and that the oxygen extraction model proposed by Chang and the hydrogen injection model by Faughnan were not valid. This result coincides with Deneuville's model, i.e. the hydrogen content within the film does not change in the reaction and that the coloring mechanism is explained by the transfer of hydrogen from a passive site to an active site within the films.