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Morphology controlled open circuit voltage in polymer solar cells |
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| Authors: | Chetan R. Singh Michael Sommer Marcel Himmerlich André Wicklein Stefan Krischok Mukundan Thelakkat Harald Hoppe |
| Affiliation: | 1. Institute of Physics and Institute of Micro‐ and Nanotechnologies, Ilmenau University of Technology, 98684 Ilmenau, Germany;2. Applied Functional Polymers, University of Bayreuth, 95440 Bayreuth, Germany;3. Present address: Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom |
| Abstract: | We report a strong dependence of open circuit voltage on the altered morphology of block copolymer (P3HT‐b ‐PPerAcr) based solar cells. The open circuit voltage increases dramatically by about 300 mV by increasing the amount of acceptor homopolymer within the block copolymer/homopolymer blends. The change in open circuit voltage is found to be in correlation with the enrichment of acceptor moiety at the film surface as identified by Atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS). Based on this fact, an additional increase in open circuit voltage to its maximum values is achieved by introducing an acceptor buffer layer at the cathode interface. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
| Keywords: | polymers organic solar cells open circuit voltage morphology block copolymers |