A molecular interaction–diffusion framework for predicting organic solar cell stability
- 11 January 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Materials
- Vol. 20 (4), 525-532
- https://doi.org/10.1038/s41563-020-00872-6
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.Keywords
Funding Information
- United States Department of Defense | United States Navy | Office of Naval Research (N000141712204, N000141712204)
- KAUST | Global Collaborative Research, King Abdullah University of Science and Technology (No. 3321, No. 3321, No. 3321, No. 3321)
- North Carolina State University (Start-up Fund, Start-up fund, Start-up funds)
- NSF | Directorate for Mathematical & Physical Sciences | Division of Astronomical Sciences (Career, CMMI-1554322)
- United States Department of Defense | United States Navy | ONR | Office of Naval Research Global (N000141712204, N00014-18-1-2448, N00014-18-1-2448)
- NSF | ENG/OAD | Division of Chemical, Bioengineering, Environmental, and Transport Systems (CBET-1639429, CBET-1639429)
- NSF | ENG/OAD | Division of Civil, Mechanical and Manufacturing Innovation (CMMI-1554322)
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