Abstract
Rapid increase in the power conversion efficiency of organic solar cells (OSCs) has been achieved with the development of non-fullerene small-molecule acceptors (NF-SMAs). Although the morphological stability of these NF-SMA devices critically affects their intrinsic lifetime, their fundamental intermolecular interactions and how they govern property–function relations and morphological stability of OSCs remain elusive. Here, we discover that the diffusion of an NF-SMA into the donor polymer exhibits Arrhenius behaviour and that the activation energy Ea scales linearly with the enthalpic interaction parameters χH between the polymer and the NF-SMA. Consequently, the thermodynamically most unstable, hypo-miscible systems (high χ) are the most kinetically stabilized. We relate the differences in Ea to measured and selectively simulated molecular self-interaction properties of the constituent materials and develop quantitative property–function relations that link thermal and mechanical characteristics of the NF-SMA and polymer to predict relative diffusion properties and thus morphological stability.
| Original language | English |
|---|---|
| Pages (from-to) | 525-532 |
| Number of pages | 8 |
| Journal | Nature Materials |
| Volume | 20 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2021 |
Bibliographical note
Publisher Copyright:© 2021, The Author(s), under exclusive licence to Springer Nature Limited.
Funding
Y.Q., Z.P., H.H., H.A. and initial work by M.G. was supported by Office of Naval Research (ONR) grant no. N000141712204 and KAUST\u2019s Center Partnership Fund (no. 3321). N.B. and B.T.O. acknowledge support by a National Science Foundation (NSF) grant (no. CMMI-1554322). T.K., A.A. and recent work by M.G. was supported by NCSU start-up funds to A.A., J.R. and W.Y. acknowledge support by an NSF grant (no. CBET-1639429). C.R. and W.M. acknowledge the support of the ONR (N00014-18-1-2448) and the NSF under Cooperative Agreement no. 1849213; supercomputing resources were provided by the Department of Defense (DoD) through the DoD High-Performance Computing Modernization Program (project no. ONRDC40433481) and by the University of Kentucky Information Technology Department and Center for Computational Sciences. SIMS measurements were performed at the Analytical Instrumentation Facility at NCSU, which is partially supported by the State of North Carolina and the National Science Foundation. C. Zhou is acknowledged for providing support for SIMS measurements. The DSC instrument was purchased with UNC-GA ROI funds. C. Zhu, A. Hexemer and C. Wang of the ALS provided instrument maintenance. E. Gomez and J. Litofsky are acknowledged for providing the initial Flory\u2013Huggins program code. L. Ye and M. Balik (NCSU) are acknowledged for fruitful discussion and input. A. Dinku is acknowledged for maintaining shared ORaCEL facilities and sharing some PBDB-T2F:Y6 stability data for reference. F. He and T. Zhao are acknowledged for help with attaining molecular weight data via high temperature gel permeation chromatography. H. Yan is acknowledged for providing ITIC-4Cl NF-SMA. I. Angunawela is acknowledged for performing complementary shelflife measurements of P3HT:EH-IDTBR devices.
| Funders | Funder number |
|---|---|
| University of Kentucky Information Technology Department and Center for Computational Sciences | |
| U.S. Department of Energy Chinese Academy of Sciences Guangzhou Municipal Science and Technology Project Oak Ridge National Laboratory Extreme Science and Engineering Discovery Environment National Science Foundation National Energy Research Scientific Computing Center National Natural Science Foundation of China | 1849213, CMMI-1554322 |
| U.S. Department of Energy Chinese Academy of Sciences Guangzhou Municipal Science and Technology Project Oak Ridge National Laboratory Extreme Science and Engineering Discovery Environment National Science Foundation National Energy Research Scientific Computing Center National Natural Science Foundation of China | |
| U.S. Department of Defense | ONRDC40433481 |
| U.S. Department of Defense | |
| Office of Naval Research Naval Academy | |
| Division of Chemical, Bioengineering, Environmental, and Transport Systems | |
| Division of Civil, Mechanical and Manufacturing Innovation | |
| Division of Astronomical Sciences | |
| Carolina Center of Cancer Nanotechnology Excellence, University of North Carolina - Chapel Hill | |
| Office of Naval Research Global | N000141712204 |
| Office of Naval Research Global | |
| University of North Carolina and North Carolina State University | CBET-1639429, N00014-18-1-2448 |
| University of North Carolina and North Carolina State University | |
| Global Collaborative Research, King Abdullah University of Science and Technology | 3321 |
| Global Collaborative Research, King Abdullah University of Science and Technology | |
| King Abdullah University of Science and Technology |
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering