Long-range exciton diffusion in non-fullerene acceptors and coarse bulk heterojunctions enable highly efficient organic photovoltaics
Abstract
We investigated singlet exciton diffusion in three ITIC derivatives used as electron acceptors in organic photovoltaics (OPVs) by time-resolved photoluminescence volume quenching and exciton–exciton annihilation. The exciton diffusion coefficient was found to be in the range of 0.003–0.007 cm2 s−1 which leads to a three-dimensional exciton diffusion length of up to 31 nm. We fabricated solar cells using bulk heterojunctions of these acceptors with the electron donor PTB7-Th which showed ∼7% efficiency and large scale phase separation. Our results show that long range exciton diffusion and large domains offer significant advantages for OPVs.
Citation
Sajjad , M T , Ruseckas , A , Jagadamma , L K , Zhang , Y & Samuel , I D W 2020 , ' Long-range exciton diffusion in non-fullerene acceptors and coarse bulk heterojunctions enable highly efficient organic photovoltaics ' , Journal of Materials Chemistry , vol. 8 , no. 31 , pp. 15687-15694 . https://doi.org/10.1039/D0TA06017H
Publication
Journal of Materials Chemistry
Status
Peer reviewed
ISSN
0959-9428Type
Journal article
Description
Funding: We acknowledge support from the European Commission (European Research Council grant 321305) and Marie Sklodowska-Curie Individual Fellowship grant 745776. We are also grateful to EPSRC for support from grants (EP/L017008/1 and EP/L012294/1).Collections
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