Acridine‐Substituted‐Centronucleus Nonfullerene Acceptors Enables Organic Solar Cells with Over 20% Efficiency with Low Nonradiative Recombination Loss

Abstract In this work, we propose a novel strategy of introducing luminescent acridine units for central nuclear substitution in quinoxaline‐based acceptor molecules (named AQx‐ o ‐Ac and AQx‐ m ‐Ac) to enhance their photoluminescence quantum yields (PLQY), which can effectively improve the electroluminescent quantum efficiency (EQE EL ) of OSCs and thereby suppress Δ E nr . In addition, the substituted acridine unit accelerates molecular aggregation and optimizes molecular crystallization, effectively alleviating the static disorder of acceptor molecules and facilitating charge extraction and transport in OSCs. As a result, the PM6:AQx‐ m ‐Ac binary OSCs achieve an excellent PCE of 18.64% with an exceptionally low Δ E nr of 0.166 eV. To the best of our knowledge, a Δ E nr of 0.166 eV represents the lowest value reported for OSCs achieving PCEs over 18 %. Finally, the acceptor AQx‐ m ‐Ac is incorporated into PM6:eC9 blend as the third component, and the optimal ternary device produces a superior PCE of 20.28%. This work highlights the potential of promoting luminescence for suppressing nonradiative energy loss and charts a viable path for upcoming breakthrough in high‐efficiency organic photovoltaics.