Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 33: Organic Photovoltaics II
CPP 33.6: Vortrag
Donnerstag, 26. März 2009, 15:15–15:30, ZEU 222
Absorption enhancement in excitonic solar cells by a photonic crystal top layer — •Stefan Guldin1, Nicolas Tetreault1,3, Mathias Kolle1, Sven Hüttner1, Mark Welland2, Peter Müller-Buschbaum4, Richard Friend1, and Ullrich Steiner1 — 1Cavendish Laboratory, University of Cambridge, UK — 2Nanoscience Center, University of Cambridge, UK — 3LPI, Ecole Polytechnique Federale de Lausanne, CH — 4Physik-Department, E13, TU München
Photonic crystal structures have been identified by theorists as a candidate to enhance the still relatively low response of excitonic photovoltaic cells in the near infrared. We present a new material route that enables the fabrication of a double layer dye-sensitised solar cell, including a mesoporous TiO2 underlayer with high surface area and an optically active TiO2 photonic crystal layer. A diblock copolymer acts as a structural directing agent for the mesoporous TiO2, arranging the sol-gel-derived material into a highly ordered nanostructure. The hybrid underlayer is not porous in its unannealed state and thus allows the self-assembly and infiltration of a photonic crystal template. This approach represents, to our knowledge, the first successful method that couples a photonic crystal top layer into a functioning dye-sensitised solar cell with front illumination, opening up a vast parameter space for effective light management. In this first attempt an increase in normalised photon to electron conversion of 20.4% was observed in the range from 520 nm to 725 nm (at the tail of the dye absorption spectrum).