title: Galvanostatic Ion Detrapping Rejuvenates Oxide Thin Films.
abstract: Ion trapping under charge insertion-extraction is well-known to degrade the electrochemical performance of oxides. Galvanostatic treatment was recently shown capable to rejuvenate the oxide, but the detailed mechanism remained uncertain. Here we report on amorphous electrochromic (EC) WO3 thin films prepared by sputtering and electrochemically cycled in a lithium-containing electrolyte under conditions leading to severe loss of charge exchange capacity and optical modulation span. Time-of-flight elastic recoil detection analysis (ToF-ERDA) documented pronounced Li(+) trapping associated with the degradation of the EC properties and, importantly, that Li(+) detrapping, caused by a weak constant current drawn through the film for some time, could recover the original EC performance. Thus, ToF-ERDA provided direct and unambiguous evidence for Li(+) detrapping.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Arvizu
authors.forename: Rui-Tao
authors.initials: RT
authors.lastname: Wen
authors.forename: Daniel
authors.initials: D
authors.lastname: Primetzhofer
authors.affiliation: Department of Engineering Physics, École Polytechnique de Montréal , Montreal, Quebec H3C 3A7, Canada.
authors.forename: Jolanta E
authors.initials: JE
authors.lastname: Klemberg-Sapieha
authors.affiliation: Department of Engineering Physics, École Polytechnique de Montréal , Montreal, Quebec H3C 3A7, Canada.
authors.forename: Ludvik
authors.initials: L
authors.lastname: Martinu
authors.forename: Gunnar A
authors.initials: GA
authors.lastname: Niklasson
authors.forename: Claes G
authors.initials: CG
authors.lastname: Granqvist
keywords: ToF-ERDA; WO3; electrochromism; ion detrapping; smart windows