Abstract
The optical properties of sputter deposited amorphous tungsten oxide films have been measured in-situ during slow electrochemical cycling in a lithium containing electrolyte. Amorphous films exhibit coloration under Li insertion and bleaching under Li extraction. Substoichiometric films show almost reversible optical changes already in the first electrochemical cycle and are completely reversible thereafter. Tungsten oxide films sputtered in a large excess of oxygen were found to be slightly overstoichiometric, as determined by Rutherford Backscattering Spectrometry. They exhibit irreversible charge transfer and coloration in the first cycle. Thereafter they cannot be completely bleached and exhibit transmittance contrast between coloured and partially bleached states. The irreversible colouration of the stoichiometric films is associated with a feature at 2.6 to 2.9 eV vs. Li in electrochemical measurements. Possible chemical reactions giving rise to this behaviour are discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
