title: Promising Strategy To Improve Charge Separation in Organic Photovoltaics: Installing Permanent Dipoles in PCBM Analogues.
abstract: A multidisciplinary approach involving organic synthesis and theoretical chemistry was applied to investigate a promising strategy to improve charge separation in organic photovoltaics: installing permanent dipoles in fullerene derivatives. First, a PCBM analogue with a permanent dipole in the side chain (PCBDN) and its reference analogue without a permanent dipole (PCBBz) were successfully synthesized and characterized. Second, a multiscale modeling approach was applied to investigate if a PCBDN environment around a central donor-acceptor complex indeed facilitates charge separation. Alignment of the embedding dipoles in response to charges present on the central donor-acceptor complex enhances charge separation. The good correspondence between experimentally and theoretically determined electronic and optical properties of PCBDN, PCBBz, and PCBM indicates that the theoretical analysis of the embedding effects of these molecules gives a reliable expectation for their influence on the charge separation process at a microscopic scale in a real device. This work suggests the following strategies to improve charge separation in organic photovoltaics: installing permanent dipoles in PCBM analogues and tuning the concentration of these molecules in an organic donor/acceptor blend.
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Hilde D
authors.initials: HD
authors.lastname: de Gier
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.|Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Jahani
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Ria
authors.initials: R
authors.lastname: Broer
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.|Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Hummelen
authors.affiliation: Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.|Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.|Ghent Quantum Chemistry Group, Department of Inorganic and Physical Chemistry, Ghent University , Krijgslaan 281 (S3), B-9000 Gent, Belgium.
authors.forename: Remco W A
authors.initials: RW
authors.lastname: Havenith