Electrochromic materials and devices

Abstract

Fabrication and operation of two simple electrochromic device using ethyl viologen in a polymer matrix is presented here. Open-face and cross- bar geometry device fabricated for the study of various oxidation state of ethyl viologen (EV) using Raman and UV-Vis spectroscopy. We demon- strated absorption modulation and Raman peak shift by changing bias across device. To nd out structural changes inside the molecule with ap- plied bias, in-situ Raman spectroscopy is used. As the biasing increases corresponding Raman peaks intensity increase represent the formation of free radical cation. To measure changes in absorbance and kinetics study with respect to applied bias of the device in-situ UV-Vis spectroscopy used. Raman and UV-Vis spectroscopy is combine study to nd out fundamental reason of colour changes of viologen molecule. Keywords: Raman spec- troscopy, UV-Vis spectroscopy, Viologen, Electrochromism