Electrochromic stability of WO3 thin films with nanometer-scale periodicity and varying degrees of crystallinity - Research portal of Justus Liebig University Giessen:

Journal article

Electrochromic stability of WO3 thin films with nanometer-scale periodicity and varying degrees of crystallinity

Authors list: Sallard, S; Brezesinski, T; Smarsly, BM

Publication year: 2007

Pages: 7200-7206

Journal: Journal of Physical Chemistry C

Volume number: 111

Issue number: 19

ISSN: 1932-7447

DOI Link: https://doi.org/10.1021/jp068499s

Publisher: American Chemical Society

Abstract:
Electrochromic tungsten oxide (WO3) thin films with nanometer-scale porosity have been synthesized via a sol-gel procedure making use of evaporation-induced self-assembly. According to wide-angle X-ray scattering data combined with electrochemical analyses, the degree of crystallinity ranging from fully amorphous to 100% crystalline can be adjusted by straightforward annealing. The three-dimensional cubic pore structure is thereby almost not affected. Aside from the material characterization, in this work we specifically focus on the overall electrochemical and electrochromic behavior (coloration efficiency, charge capacity, etc.) upon changes in the operating temperature. As a main result, only the mesoporous highly crystalline WO3 films display long-term cycling stability under realistic environmental conditions. We further demonstrate that sufficient crystallinity is needed to ensure stability of the inherent electrochemical properties at high operating temperatures (up to 70 degrees C). Thus, only the WO3 films with a highly crystalline framework exhibit almost unchanged electrochemical/electrochromic characteristics after prolonged potentiostatic cycling and exposure to elevated operating temperatures. In contrast, amorphous and partially crystalline films suffer from irreversible performance degradation due to structural modifications.

Authors/Editors

- Uni.-Prof. Dr. Bernd Michael Smarsly

Citation Styles

Harvard Citation style: Sallard, S., Brezesinski, T. and Smarsly, B. (2007) Electrochromic stability of WO3 thin films with nanometer-scale periodicity and varying degrees of crystallinity, Journal of Physical Chemistry C, 111(19), pp. 7200-7206. https://doi.org/10.1021/jp068499s

APA Citation style: Sallard, S., Brezesinski, T., & Smarsly, B. (2007). Electrochromic stability of WO3 thin films with nanometer-scale periodicity and varying degrees of crystallinity. Journal of Physical Chemistry C. 111(19), 7200-7206. https://doi.org/10.1021/jp068499s