TY - JOUR
T1 - Structural correlations in the generation of polaron pairs in low-bandgap polymers for photovoltaics
AU - Tautz, Raphael
AU - Da Como, Enrico
AU - Limmer, Thomas
AU - Feldmann, Jochen
AU - Egelhaaf, Hans-Joachim
AU - Von Hauff, Elizabeth
AU - Lemaur, Vincent
AU - Beljonne, David
AU - Yilmaz, Seyfullah
AU - Dumsch, Ines
AU - Allard, Sybille
AU - Scherf, Ullrich
PY - 2012/7/24
Y1 - 2012/7/24
N2 - Polymeric semiconductors are materials where unique optical and electronic properties often originate from a tailored chemical structure. This allows for synthesizing conjugated macromolecules with ad hoc functionalities for organic electronics. In photovoltaics, donor–acceptor co-polymers, with moieties of different electron affinity alternating on the chain, have attracted considerable interest. The low bandgap offers optimal light-harvesting characteristics and has inspired work towards record power conversion efficiencies. Here we show for the first time how the chemical structure of donor and acceptor moieties controls the photogeneration of polaron pairs. We show that co-polymers with strong acceptors show large yields of polaron pair formation up to 24% of the initial photoexcitations as compared with a homopolymer (η=8%). π-conjugated spacers, separating the donor and acceptor centre of masses, have the beneficial role of increasing the recombination time. The results provide useful input into the understanding of polaron pair photogeneration in low-bandgap co-polymers for photovoltaics.
AB - Polymeric semiconductors are materials where unique optical and electronic properties often originate from a tailored chemical structure. This allows for synthesizing conjugated macromolecules with ad hoc functionalities for organic electronics. In photovoltaics, donor–acceptor co-polymers, with moieties of different electron affinity alternating on the chain, have attracted considerable interest. The low bandgap offers optimal light-harvesting characteristics and has inspired work towards record power conversion efficiencies. Here we show for the first time how the chemical structure of donor and acceptor moieties controls the photogeneration of polaron pairs. We show that co-polymers with strong acceptors show large yields of polaron pair formation up to 24% of the initial photoexcitations as compared with a homopolymer (η=8%). π-conjugated spacers, separating the donor and acceptor centre of masses, have the beneficial role of increasing the recombination time. The results provide useful input into the understanding of polaron pair photogeneration in low-bandgap co-polymers for photovoltaics.
UR - http://www.scopus.com/inward/record.url?scp=84864860431&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1038/ncomms1967
U2 - 10.1038/ncomms1967
DO - 10.1038/ncomms1967
M3 - Article
SN - 2041-1723
VL - 3
JO - Nature Communications
JF - Nature Communications
M1 - 970
ER -