Mechanism of electrochemical deposition and coloration of electrochromic V2O5 nanothin film: An in situ x-ray spectroscopy study
Ying-Rui Lu1*, Tzung-Zing Wu5, Chi-Liang Chen4, Da-Hau Wei5, Wu-Ching Chou3, Chung-Li Dong2
1Program for Science and Technology of Accelerator Light Source, National Chiao Tung University, Hsinchu, Taiwan
2Department of Physics, Tamkang University, New Taipei City, Taiwan
3Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
4National Synchrotron Radiation Research Center (NSRRC), Hsinchu, Taiwan
5Department of Mechanical Engineering and Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, Taiwan
* presenting author:Ying-Rui Lu,
Electrochromic switching devices have elicited considerable attention because these thin films are among the most promising materials for energy-saving applications. The vanadium oxide system is simple and inexpensive because only a single-layer film of this material is sufficient for coloration. Vanadium dioxide thin films are fabricated by electrochemical deposition and cyclic voltammetry. Chronoamperometric analyses have indicated that the thin V2O5 film demonstrates faster intercalation and deintercalation of lithium ions than those of the thick V2O5 film, benefiting the coloration rate. Despite substantial research on the synthesis of vanadium oxides, the monitoring of electronic and atomic structures during growth and coloration of such material has not been thoroughly examined. In the present study, in situ X-ray absorption spectroscopy (XAS) is employed to determine the electronic and atomic structures of V2O5 thin films during electrochemical growth and then electrochromic coloration. In situ XAS results demonstrate the growth mechanism of the electrodeposited V2O5 thin film and suggest that its electrochromic performance strongly depends on the local atomic structure. This study improves our understanding of the electronic and atomic properties of the vanadium oxide system grown by electrochemical deposition and enhances the design of electrochromic materials for potential energy-saving applications.

Keywords: X-ray absorption spectroscopy, In situ x-ray spectroscopy, Electrochemical, Vanadium oxides