Suppression of Charge Recombination Induced by Solid Additive Assisting Organic Solar Cells with Efficiency over 20.

A volatile solid additive strategy, which can effectively optimize the morphology of the photoactive layer with an ideal domain size and purity, has emerged as a promising approach to improve the photovoltaic performance of organic solar cells (OSCs). However, the precise role of solid additives in modulating charge and exciton dynamics, especially the recombination process, remains not fully understand. In this study, a solid additive, 1,4-diiodo-2,5-dimethoxybenzene (DIDOB), is developed to improve the photovoltaic performance of OSCs and conduct a comprehensive investigation into its effect on the charge recombination process.

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

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) of OSCs and thereby suppress ΔE. 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.

Isomeric Dimer Acceptors for Stable Organic Solar Cells with over 19 % Efficiency.

The strategy of isomerization is known for its simple yet effective role in optimizing molecular configuration and enhancing the power conversion efficiency (PCE) of organic solar cells (OSCs). However, the impact of isomerization on the design of dimer acceptors has been rarely investigated, and the relationship between the chemical structure and optoelectronic property remains unclear. In this study, we designed and synthesized two dimer acceptor isomers named D-TPh and D-TN, which differ in the positional arrangement of their end capping groups.

Regulating Electron-Phonon Coupling by Solid Additive for Efficient Organic Solar Cells.

Strong electron-phonon coupling can hinder exciton transport and induce undesirable non-radiative recombination, resulting in a shortened exciton diffusion distance and constrained exciton dissociation in organic solar cells (OSCs). Therefore, suppressing electron-phonon coupling is crucially important for achieveing high-performance OSCs. Here, we employ the solid additive to regulating electron-phonon coupling in OSCs.

Conjugation-Broken Dimer Acceptors Enable High-Efficiency, Stable, and Flexibility-Robust Organic Solar Cells.

Dimer acceptors in organic solar cells (OSCs) offer distinct advantages, including a well-defined molecular structure and excellent batch-to-batch reproducibility. Their high glass transition temperature (T) aids in achieving an optimal kinetic morphology, thereby enhancing device stability. Currently, most of dimer acceptor materials are linked with conjugated units in order to obtain high power conversion efficiencies (PCEs).

Facile, Versatile and Stepwise Synthesis of High-Performance Oligomer Acceptors for Stable Organic Solar Cells.

Oligomer acceptors have recently emerged as promising photovoltaic materials for achieving high power conversion efficiency (PCE) and long-term stability in organic solar cells (OSCs). However, the limited availability of diverse acceptors, resulting from the sole synthetic approach, has hindered their potential for future industrialization. In this study, we present a facile and effective stepwise approach that utilizes two consecutive Stille coupling reactions for the synthesis of oligomer acceptors.

Over 18% Efficiency of All-Polymer Solar Cells with Long-Term Stability Enabled by Y6 as a Solid Additive.

Morphology control greatly influences the power conversion efficiency (PCE) and long-term stability of all-polymer solar cells (all-PSCs); however, it remains challenging owing to their complex crystallization behavior. Herein, a small amount of Y6 (2 wt%) is introduced as a solid additive into a PM6:PY-DT blend. Y6 remained inside the active layer and interacted with PY-DT to form a well-mixed phase.