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RESEARCH PRODUCT
Coloration mechanism of electrochromic Na x WO3 thin films
David HorwatClotilde BoulangerManuel TresseAlexandre ZimmerKessein Eric TillousLaurent BrochMickaël GilliotNicolas Steinsubject
010302 applied physicsAlkali ions[PHYS]Physics [physics]Materials sciencebusiness.industry02 engineering and technology021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesTungsten trioxideAtomic and Molecular Physics and OpticsActive layerIonchemistry.chemical_compoundOpticschemistryElectrochromismAbsorption band0103 physical sciences[CHIM]Chemical SciencesThin film0210 nano-technologybusinessTrioxidedescription
International audience; The coloration mechanism of tungsten trioxide (WO3) upon insertion of alkali ions is still under debate after several decades of research. This Letter provides new insights into the reversible insertion and coloration mechanisms of Na+ ions in WO3 thin films sputter-deposited on ITO/glass substrates. A unique model based on a constrained spline approach was developed and applied to draw out ε1+iε2 from spectroscopic ellipsometry data from 0.6 to 4.8 eV whatever the state of the electrochromic active layer, i.e. as-deposited, colored or bleached. It is shown that electrochemically intercalated sodium-tungsten trioxide, NaxWO3 (x=0.1, 0.2, 0.35), exhibits an absorption band centered at ca.1.14 eV in 2 governing the coloration mechanism.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-02-19 |