Jensen, Jacob1; Hösel, Markus1; Kim, Inyoung4; Yu, Jong-Su4; Jo, Jeongdai4; Krebs, Frederik C1
1 Department of Energy Conversion and Storage, Technical University of Denmark2 Functional organic materials, Department of Energy Conversion and Storage, Technical University of Denmark3 Korea Institute of Machinery and Materials4 Korea Institute of Machinery and Materials
Indium-doped tin oxide free electrochromic devices are prepared by coating electrochromic polymers onto polyethylene terephthalate substrates encompassing two different silver grids as electrodes. One design comprises a fl exoprinted highly conductive silver grid electrode, yielding electrochromic devices with a response time of 2 s for an optical contrast of 27%. The other design utilizes an embedded silver grid electrode whereupon response times of 0.5 s for a 30% optical contrast are realized when oxidizing the device. A commercially available conductive poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate acid) formulation (PEDOT:PSS) is coated onto the silver grids as a charge balancing polymer, and is in this setting found to be superior to a polypyrrole previously employed in electrochromic devices. In addition, the PEDOT:PSS layer increases the conductivity in the hexagonal grid structure.
Advanced Functional Materials, 2014, Vol 24, p. 1228-1233