Sub-picosecond charge-transfer at near-zero driving force in polymer:non-fullerene acceptor blends and bilayers

Zhong, Yufei; Causa', Martina; Moore, Gareth John; Krauspe, Philipp; Xiao, Bo; Günther, Florian; Kublitski, Jonas; Shivhare, Rishi; Benduhn, Johannes; BarOr, Eyal; Mukherjee, Subhrangsu; Yallum, Kaila M.; Réhault, Julien; Mannsfeld, Stefan C. B.; Neher, Dieter; Richter, Lee J.; DeLongchamp, Dean M.; Ortmann, Frank; Vandewal, Koen; Zhou, Erjun; ... (2020). Sub-picosecond charge-transfer at near-zero driving force in polymer:non-fullerene acceptor blends and bilayers. Nature Communications, 11(1) Springer Nature 10.1038/s41467-020-14549-w

s41467-020-14549-w.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).
Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit

Download (1MB) | Preview

Organic photovoltaics based on non-fullerene acceptors (NFAs) show record efficiency of 16 to 17% and increased photovoltage owing to the low driving force for interfacial charge- transfer. However, the low driving force potentially slows down charge generation, leading to a tradeoff between voltage and current. Here, we disentangle the intrinsic charge-transfer rates from morphology-dependent exciton diffusion for a series of polymer:NFA systems. Moreover, we establish the influence of the interfacial energetics on the electron and hole transfer rates separately. We demonstrate that charge-transfer timescales remain at a few hundred femtoseconds even at near-zero driving force, which is consistent with the rates predicted by Marcus theory in the normal region, at moderate electronic coupling and at low re-organization energy. Thus, in the design of highly efficient devices, the energy offset at the donor:acceptor interface can be minimized without jeopardizing the charge-transfer rate and without concerns about a current-voltage tradeoff.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP)

UniBE Contributor:

Zhong, Yufei, Causa', Martina, Moore, Gareth John, Krauspe, Philipp Jonathan, Yallum, Kaila Morgan, Réhault, Julien Emile, Banerji, Natalie


500 Science > 540 Chemistry




Springer Nature


[4] Swiss National Science Foundation




Olivier Nicolas Ludovic Bardagot

Date Deposited:

02 Mar 2020 16:14

Last Modified:

05 Dec 2022 15:36

Publisher DOI:


Related URLs:

Additional Information:

Funding sources:
- SNSF: Type: Förderungsprofessur, Grant number: PP00P2_150536
- University of Bern




Actions (login required)

Edit item Edit item
Provide Feedback