Electrochemical aspects of display technology based on nanostructured titanium dioxide with attached viologen chromophores
2008 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 0019-4686, ISSN 0013-4686, Vol. 53, no 11, 4065-4071 p.Article in journal (Refereed) Published
Progress in recent years in the field of electrochromic displays based on viologen modified high-surface area TiO2 electrodes (Vio(2+)/TiO2) has moved the technology towards commercialisation. Viologen molecules (Vio(2+)), derivatised with phosphonic acid attachment groups can be chemisorbed on nanostructured TiO2 layers of thickness 2-10 mu m. Characterisation by cyclic voltammetry, spectroelectrochemistry and impedance spectroscopy demonstrates that colourless Vio(2+)/TiO2 is reversibly reduced to the strongly coloured cation radical species Vio(+center dot)/TiO2. This system can constitute the working electrode of an electrochromic display with a capacitive doped SnO2 electrode as counter electrode, the latter coated by an electrochemically inert white fight-reflecting layer. Such a device is stable upon repeated colouration-bleaching cycles with a bleached-to-coloured state contrast ratio exceeding 5. Multicolour displays can be achieved by patterning different electrochromophores onto different areas of one working electrode. (C) 2007 Elsevier Ltd. All rights reserved.
Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD , 2008. Vol. 53, no 11, 4065-4071 p.
electrochromic display; nanostructured electrode; viologen; titanium dioxide; Nanochromics (TM)
IdentifiersURN: urn:nbn:se:uu:diva-152027DOI: 10.1016/j.electacta.2007.10.011OAI: oai:DiVA.org:uu-152027DiVA: diva2:412154