Dresden 2011 – scientific programme
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O: Fachverband Oberflächenphysik
O 73: [DS] Organic Electronics and Photovoltaics III (jointly with CPP, HL, and O)
O 73.8: Talk
Thursday, March 17, 2011, 15:45–16:00, GER 38
Dye directed changes in ZnO matrices in organic/inorganic photovoltaic systems — •Harald Graaf1, Franziska Lüttich1, Mirko Kehr1, Christian Dunkel2, and Torsten Oekermann2 — 1Institut für Physik, Technische Universität Chemnitz, 09107 Chemnitz — 2Institut für Physikalische Chemie und Elektrochemie, Leibniz Universität Hannover, 30167 Hannover
Dye-sensitized photovoltaic cells with zinc oxide (ZnO) as the inorganic semiconductor and organic dye molecules as the sensitizer are well-known devices with high efficiency. Such cells are prepared by electrochemical deposition of an aqueous zinc salt solution including dye molecules. After deposition the dye is desorbed to obtain a porous ZnO network followed by re-adsorption of the dye as a sensitizer. The dye molecules influence the crystal orientation of the ZnO as they tend to physisorb on different crystal surfaces.
We will present recent results on as-deposited and desorbed dye/ZnO films obtained by different analytic methods: X-ray investigations, Scanning Electron Microscopy, Atomic and Kelvin probe force microscopy and optical spectroscopy. This allows a deep insight into the dye/semiconductor system, which is necessary to improve the efficiency of such devices. Here the focus is on crystal orientation, morphology and work function of the ZnO matrix. Also the arrangement of the dye molecules in as well as on top of the as-deposited films and the band edge of the zinc oxide is accessible.