Balancing driving force, charge transport, and non-radiative recombination in organic solar cells with non-fused ring acceptors
Year: 2025
Type: article
Abstract: The design of low-cost, stable, and high-efficiency non-fullerene acceptors requires a deeper understanding of the impact of the molecular structure on photovoltaic performance. In this study, we investigate the influence of gradual side-chain modifications of non-fused ring acceptors. The transition from non- (L0) to partially (L2) and fully chlorinated (L4) side chains enhances the molecular self-assembly, condenses the intermolecular packing, and balances the electron and hole mobility. Additionally, we observe lower bimolecular recombination coefficients and field-independent exciton dissociation upon gradual chlorination of the side chains, which improves the fill factor of the devices. However, the accompanying higher non-radiative voltage loss restricts the performance of the fully chlorinated L4 systems. Thus, the blend PM6:L2 balances efficient exciton dissociation with reduced non-radiative recombination, yielding the highest efficiency. This study emphasizes the pivotal role of side-chain halogenation in fine-tuning molecular packing and charge dynamics, offering guidelines for the next generation high efficiency photovoltaic materials.
Source: EES solar.
DOI: 10.1039/d5el00136f
Institutions: IMEC, Zhejiang University, Hasselt University, University of Potsdam
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
Funders: Deutsche Forschungsgemeinschaft, National Natural Science Foundation of China, Fonds Wetenschappelijk Onderzoek, Zhejiang University, Universiteit Hasselt, Vlaamse regering, European Research Council, National Key Research and Development Program of China, Fundamental Research Funds for the Central Universities
Awards: SOFIA: Self-powered upconverter foil for renewable energies and advanced imaging., G2508694568, G2839177744, Verständnis der Quanteneigenschaften von angeregten Zuständen an der DonatorAkzeptorGrenzfläche – auf dem Weg zu effizienten organischen Solarzellen mit minimalem Energieverlust, Den Füllfaktor von auf NonFullerenAkzeptor basierenden Solarzellen über 80% erhöhen: Der Zusammenhang zwischen Ordnung, reduzierten Rekombinationsverlusten und Bauteilperformance, G4928266564, Organic spintronics based on intrinsically paramagnetic polymers, G6329373278, G8008244658
OpenAlex ID: W4416815445