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Calamatic liquid crystal blends for organic photovoltaics

Kelly, Stephen M.; Lei, Chunghong; Al Khalifah, Manea S.; O'Neill, Mary; Aldred, Matthew P.; Kitney, Stuart P.; Vlachos, Panagiotis; Kelly, Stephen M.


Stephen M. Kelly

Chunghong Lei

Manea S. Al Khalifah

Mary O'Neill

Matthew P. Aldred

Stuart P. Kitney

Panagiotis Vlachos

Stephen M. Kelly


Zakya H. Kafafi

Paul A. Lane


Four different perylene-based electron-acceptors having similar electron affinities, but different thermotropic phases are blended with nematic liquid crystalline electron-donors with a fluorene-thiophene structure to form single layer photovoltaic devices. Best results are obtained when the nematic donor is mixed with an amorphous acceptor to give a supercooled nematic glass at room temperature. Atomic force microscopy operating in the phase contrast mode reveals phase separation on a nanometer scale with a broad distribution of domain sizes peaking at 26 nm. We correlate the morphology of the different blends with the performance of the photovoltaic devices. Power conversion efficiencies up to 0.9 % are obtained with excitation at 470 nm.


Lei, C., Al Khalifah, M. S., O'Neill, M., Aldred, M. P., Kitney, S. P., Vlachos, P., & Kelly, S. M. Calamatic liquid crystal blends for organic photovoltaics. Paper presented at Organic Photovoltaics IX

Presentation Conference Type Conference Paper (unpublished)
Conference Name Organic Photovoltaics IX
Acceptance Date Dec 31, 2008
Publication Date Aug 28, 2008
Journal Proceedings of SPIE - The International Society for Optical Engineering
Print ISSN 0277-786X
Publisher Society of Photo-optical Instrumentation Engineers
Peer Reviewed Peer Reviewed
Volume 7052
Article Number 705214
Pages 0 - 0
Keywords Organic photovoltaics, bulk heterojunction, liquid crystals, organic semiconductors, atomic force microscopy
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