Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 58: Poster Session III (Solid-liquid interfaces; Scanning probe and other methods; Electronic structure theory; Spin-orbit interaction)
O 58.81: Poster
Mittwoch, 13. März 2013, 18:15–21:45, Poster B1
Electrochromic coatings based on an electron-conducting vapour-deposited organic semiconductor — •Juliane Weissbecker and Derck Schlettwein — Institute of Applied Physics, Justus Liebig University of Giessen, Heinrich Buff-Ring 16, 35392 Giessen, Germany
Thin films of phthalocyanine molecules are interesting for applications as electrochromic layers because of their strong light absorption and the strong change of colour upon oxidation or reduction. Because of instable cycling during oxidation, molecules are sought that are easily reduced (high electron affinity). The redox behaviour of vapour-deposited thin films (50 nm) of F16PcCu was studied using simultaneous cyclic voltammetry and UV/Vis-spectroscopy. Upon electrochromic charging of the films electroneutrality has to be preserved by intercalating ions. The measurements were performed in contact to different electrolyte solutions and the influence of K+, Na+ or Li+ ions is discussed. During an initial conditioning cycle a decrease of the cristallinity of the thin films was found and correlated with the ion diameter. An influence of ion diffusion on the overall current was not found. Almost constant potentials independent of the electrolyte were seen for the first reduction but differences were observed in subsequent waves. These differences are again correlated to the ion diameter and, hence, the interaction potential with the reduced molecules in the films.