Skip to Main content Skip to Navigation
Journal articles

Coloration mechanism of electrochromic Na x WO3 thin films

Abstract : 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.
Document type :
Journal articles
Complete list of metadata
Contributor : LAURENT BROCH Connect in order to contact the contributor
Submitted on : Monday, July 12, 2021 - 3:14:12 PM
Last modification on : Friday, August 5, 2022 - 11:25:01 AM
Long-term archiving on: : Wednesday, October 13, 2021 - 6:38:55 PM


Files produced by the author(s)


Distributed under a Creative Commons Attribution 4.0 International License



Alexandre Zimmer, Mickaël Gilliot, Manuel Tresse, Laurent Broch, Kessein Eric Tillous, et al.. Coloration mechanism of electrochromic Na x WO3 thin films. Optics Letters, Optical Society of America - OSA Publishing, 2019, 44 (5), pp.1104-1107. ⟨10.1364/OL.44.001104⟩. ⟨hal-02900737⟩



Record views


Files downloads