A Kinetic–Energetic Bottleneck of Charge-Transfer Injection Governs Energy Loss in Organic Solar Cells

Wang R, Osterrieder T, Shukla A, Chochos CL, Gregoriou VG, He Y, Tang H, Haffner-Schirmer J, Forberich K, Li N, Heumüller T, Laquai F, Hauch J, Shoaee S, Neher D, Lüer L, Brabec C (2026)

Publication Type: Journal article

Publication year: 2026

Journal

DOI: 10.1002/aenm.71177

Abstract

The charge-transfer (CT) state in organic solar cells constitutes a kinetic–energetic bottleneck that simultaneously controls charge generation and nonradiative voltage loss. By combining time-resolved photoluminescence (100 ps–20 ns) with a physics-constrained Bayesian optimization framework, we show that the multidimensional kinetic network collapses onto a single emergent descriptor: the effective CT injection rate, kCT. Crucially, kCT is not a microscopic rate constant but a renormalized collective parameter arising from the coupled competition among exciton injection, CT population redistribution, and CT nonradiative recombination. Across six donor–acceptor systems spanning nearly two orders of magnitude in kCT, we uncover a universal scaling: each decade increase in injection rate incurs an additional ∼85 meV nonradiative energy loss. This scaling reveals an intrinsic kinetic–energetic trade-off imposed by the topology of the CT manifold—accelerating injection inevitably amplifies recombination loss. Breaking this bottleneck requires restructuring the CT network to decouple charge dissociation from recombination pathways, offering a route beyond the present voltage ceiling of organic photovoltaics.

Authors with CRIS profile

Involved external institutions

King Abdullah University of Science and Technology (KAUST) / جامعة الملك عبد الله للعلوم و التقنية Saudi Arabia (SA) Universität Potsdam Germany (DE) Advent Technologies SA Greece (GR) South China University of Technology (SCUT) / 华南理工大学 China (CN)

How to cite

APA:

Wang, R., Osterrieder, T., Shukla, A., Chochos, C.L., Gregoriou, V.G., He, Y.,... Brabec, C. (2026). A Kinetic–Energetic Bottleneck of Charge-Transfer Injection Governs Energy Loss in Organic Solar Cells. Advanced Energy Materials. https://doi.org/10.1002/aenm.71177

MLA:

Wang, Rong, et al. "A Kinetic–Energetic Bottleneck of Charge-Transfer Injection Governs Energy Loss in Organic Solar Cells." Advanced Energy Materials (2026).

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