Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films
2015 (English)In: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 14, 996-1001 p.Article in journal (Refereed) Published
There is keen interest in the use of amorphous WO3 thin films as cathodic electrodes in transmittance-modulating electrochromic devices1–4. However, these films suer from ion-trapping-induced degradation of optical modulation and reversibility on extended LiC-ion exchange. Here,we demonstrate that ion-trapping-induced degradation, which is commonly believed to be irreversible, can be successfully eliminatedby constant-current-driven de-trapping; that is, WO3 films can be rejuvenated and regain their initial highly reversible electrochromic performance. Pronounced ion trapping occurs when x exceeds 0.65 in LixWO3 during ion insertion. We find two main kinds of Li+-ion-trapping site (intermediate and deep) in WO3, where the intermediate ones are most prevalent. Li+ ions can be completely removed from intermediate traps but are irreversibly bound in deep traps. Our results provide a general framework for developing and designing superior electrochromic materials and devices.
Place, publisher, year, edition, pages
2015. Vol. 14, 996-1001 p.
WO3 films, electrochromic, variable-transmittance windows, ion-trapping
IdentifiersURN: urn:nbn:se:uu:diva-264725DOI: 10.1038/nmat4368ISI: 000361771800018OAI: oai:DiVA.org:uu-264725DiVA: diva2:861192
FunderEU, European Research Council, 267234