Influence of electric fields on morphology and performance of compatibilized all-polymer solar cells

• Applicants: Professor Dr. Michael Sommer; Dr. Uli Würfel
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2008 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 66107158

The project is an interdisciplinary approach combining chemistry and interface science (Ludwigs) and device engineering (Würfel) to study the influence of highly ordered nanostructures within se-miconducting polymer/inorganic hybrid solar cells. Thiophene based polymers and nanosized ZnO will be used as model system. Highly interdigitating donor/acceptor networks with dimensions on the scale of the exciton diffusion length will be tailor-made to achieve both a high interfacial area between the donor and the acceptor and a minimization of the transport pathlengths of the charge carriers to the electrodes. In a first approach, the influence of electric fields and controlled solvent vapor atmospheres on the alignment of ZnO nanorods within a matrix of semiconducting polymer will be studied in-situ on interdigitated nanoelectrode arrays. In a second approach, highly ordered 2 arrays of ZnO and polymer nanorods will be prepared by block copolymer self assembly and sol-vent-aided nanoimprint lithography, respectively. These templates will subsequently be infiltrated with the complementary component. Novel solar cell design principles and variation of electrode materials will be used to engineer the semiconductor/electrode interfaces. The influence of ordered morphologies on the transport of charge carriers and the overall device performance will be eluci-dated with various characterization methods. Optical and electrical modelling of solar cells shall provide deeper insight in the device physics and evaluate the optimization potential of different morphologies.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1355: Elementary Processes of Organic Photovoltaics