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.

Abstract

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.

Citation

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• Presentation Conference Type: Conference Paper (unpublished)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
• DOI: https://doi.org/10.1117/12.794260
• Keywords: Organic photovoltaics, bulk heterojunction, liquid crystals, organic semiconductors, atomic force microscopy
• Public URL: https://hull-repository.worktribe.com/output/400292