Dresden 2009 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 18: Layer Properties: Electrical, Optical and Mechanical Properties II
DS 18.1: Vortrag
Mittwoch, 25. März 2009, 11:15–11:30, GER 37
Switchable electro-optical properties of chromophore/ polymer/ metal nanocomposites near the percolation threshold — •Christina Pakula1, Christian Hanisch1, Vladimir Zaporojtchenko1, Thomas Strunskus1, Franz Faupel1, and Rainer Herges2 — 1Materialverbunde, Institut für Materialwissenschaft, CAU Kiel, Kaiserstr. 2, 24143 Kiel — 2Otto Diels-Institut, CAU Kiel, Otto-Hahn-Platz 3/4, 24118 Kiel
Chromophores are under interest nowadays because of their light induced conformational change leading to e.g. a higher dipole moment. Inside a polymer matrix the isomerization leads to switchable changes in the physical properties. The optical switching of two different azobenzene ethers dissolved in a PMMA matrix in combination with a 2D nanoparticle gold array were studied. These may be used as light switchable sensors. The chromophore/polymer film was prepared by spin-coating. The metal clusters were deposited either by thermal evaporation or sputtering. Different mixing ratios of PMMA and the two azobenzene ethers and their absorption behaviors in the UV/Vis region have been examined. The new azobenzene ether with a branched side chain had a higher absorption at the same conditions and filling factors than the first azobenzene ether. Furthermore there was no separation of polymer and azobenzene ether with the second molecule. Also the time dependencies of the switching behavior exposed to UV and visible light and the influence of the gold clusters on the switching times were examined. Finally the photoswitchable changes in resistance of the 2D-Au nanocomposite films will be discussed.