Efficient Exciton Diffusion in Organic Bilayer Heterojunctions with Nonfullerene Small Molecular Acceptors

Lee TH, Park SY, Park WW, Du X, Son JH, Li N, Kwon OH, Woo HY, Brabec C, Kim JY (2020)

Publication Type: Journal article

Publication year: 2020

Journal

ACS Energy Letters American Chemical Society

Book Volume: 5

Pages Range: 1628-1635

Journal Issue: 5

DOI: 10.1021/acsenergylett.0c00564

Abstract

Solution-processed bilayer organic solar cells (OSCs) with high performance are demonstrated for nonfullerene small molecular acceptors (NFAs). Unlike fullerene acceptors, NFAs show significant spectral overlap between their absorption and the photoluminescence (PL) of a polymer donor, which makes the design of an efficient exciton-harvesting bilayer heterojunction possible. Efficient exciton diffusion in the organic bilayer heterojunction is realized by long-range energy transfer between a polymer donor and NFAs. We observed efficient exciton diffusion from the polymer/NFA bilayer heterojunctions via thickness-dependent PL quenching and time-resolved PL measurements. Despite the strongly reduced donor-acceptor interface area, a substantial density of charge-transfer states is observed for the polymer/NFA bilayer heterojunctions by electroluminescence measurements. Overall, polymer/NFA bilayer heterojunction OSCs demonstrate a power conversion efficiency of 9%-10%, which is comparable to the photovoltaic performance of bulk heterojunction OSCs, with the additional advantage of simplified microstructure formation.

Authors with CRIS profile

Xiaoyan Du Institute Materials for Electronics and Energy Technology (i-MEET) Ning Li Institute Materials for Electronics and Energy Technology (i-MEET) Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET)

Involved external institutions

Ulsan National Institute of Science and Technology (UNIST) / 울산과학기술원 KR Korea, Republic of (KR) Korea University KR Korea, Republic of (KR)

How to cite

APA:

Lee, T.H., Park, S.Y., Park, W.-W., Du, X., Son, J.H., Li, N.,... Kim, J.Y. (2020). Efficient Exciton Diffusion in Organic Bilayer Heterojunctions with Nonfullerene Small Molecular Acceptors. ACS Energy Letters, 5(5), 1628-1635. https://dx.doi.org/10.1021/acsenergylett.0c00564

MLA:

Lee, Tack Ho, et al. "Efficient Exciton Diffusion in Organic Bilayer Heterojunctions with Nonfullerene Small Molecular Acceptors." ACS Energy Letters 5.5 (2020): 1628-1635.

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