Ultrafast charge transfer in operating bulk heterojunction solar cells.

Adv Mater

Center for Polymers and Organic Solids, University of California, Santa Barbara, CA, 93106-5090, USA; State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, PR China.

Published: March 2015

The ultrafast charge generation process in organic solar cell devices is investigated by transient reflection spectroscopy on five state-of-the-art bulk heterojunction systems. The charge generation process in operating devices is found to be a combination of an ultrafast generation mechanism over several hundred femto-seconds and a slow process from pico-seconds to nanoseconds, limited by exciton diffusion dynamics. In addition, the lack of electric field dependence in the charge dynamics rules out geminate recombination as an important loss mechanism.

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http://dx.doi.org/10.1002/adma.201405284DOI Listing

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