Nanomorphology and charge generation in bulk heterojunctions based on low-bandgap dithiophene polymers with different bridging atoms

Morana M, Azimi H, Dennler G, Egelhaaf HJ, Scharber M, Forberich K, Hauch J, Gaudiana R, Waller D, Zhu Z, Hingerl K, Van Bavel SS, Loos J, Brabec C (2010)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2010

Journal

Advanced Functional Materials Wiley-VCH Verlag

Book Volume: 20

Pages Range: 1180-1188

Journal Issue: 7

DOI: 10.1002/adfm.200900931

Abstract

Carbon bridged (C-PCPDTBT) and silicon-bridged (Si-PCPDTBT) dithiophene donor-acceptor copolymers belong to a promising class of low bandgap materials. Their higher field-effect mobility, as high as 10cm V s in pristine films, and their more balanced charge transport in blends with fullerenes make silicon-bridged materials better candidates for use in photovoltaic devices. Striking morphological changes are observed in polymer:fullerene bulk heterojunctions upon the substitution of the bridging atom. XRD investigation indicates increased π-π stacking in Si-PCPDTBT compared to the carbon-bridged analogue. The fluorescence of this polymer and that of its counterpart C-PCPDTBT indicates that the higher photogeneration achieved in Si-PCPDTBT:fullerene films (with either [C60]PCBM or [C70]PCBM) can be correlated to the inactivation of a charge-transfer complex and to a favorable length of the donor-acceptor phase separation. TEM studies of Si-PCPDTBT:fullerene blended films suggest the formation of an interpenetrating network whose phase distribution is comparable to the one achieved in C-PCPDTBT:fullerene using 1,8-octanedithiol as an additive. In order to achieve a balanced hole and electron transport, Si-PCPDTBT requires a lower fullerene content (between 50 to 60 wt%) than C-PCPDTBT (more than 70 wt%). The Si-PCPDTBT:[C70]PCBM OBH) solar cells deliver power conversion efficiencies of over 5%. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

Authors with CRIS profile

Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET) (i-MEET)

Additional Organisation(s)

Exzellenz-Cluster Engineering of Advanced Materials (EAM)

Involved external institutions

Konarka Technologies GmbH DE Germany (DE) Konarka Austria Forschungs und Entwicklungs GmbH AT Austria (AT) Konarka Technologies, Inc. US United States (USA) (US) Eindhoven University of Technology / Technische Universiteit Eindhoven (TU/e) NL Netherlands (NL) Johannes Kepler Universität (JKU) Linz AT Austria (AT)

How to cite

APA:

Morana, M., Azimi, H., Dennler, G., Egelhaaf, H.-J., Scharber, M., Forberich, K.,... Brabec, C. (2010). Nanomorphology and charge generation in bulk heterojunctions based on low-bandgap dithiophene polymers with different bridging atoms. Advanced Functional Materials, 20(7), 1180-1188. https://doi.org/10.1002/adfm.200900931

MLA:

Morana, Mauro, et al. "Nanomorphology and charge generation in bulk heterojunctions based on low-bandgap dithiophene polymers with different bridging atoms." Advanced Functional Materials 20.7 (2010): 1180-1188.

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