Selecting Solid Additives to Control the Interaction between Polymer Donors and Additives for Constructing High-Efficiency Organic Solar Cells

The utilization of volatile solid additives has emerged as a promising approach to optimize the morphology and enhance the performance of organic solar cells (OSCs). This work presents a new insight that investigates the intermolecular interactions between polymer donors and volatile solid additives to induce a favorable morphology of the blend films for high-efficiency OSCs. Simulations and experiments demonstrate that the increased interaction between the additive and the polymer donor's electron-withdrawing unit would contribute to the ordered packing of blend film. Ultimately, the altered charge separation and transport lead to different photoelectric properties of devices, which also proves that the interaction between the solid additives and the donor cannot be ignored. Because of the strongest interaction between m-DBDF and the fluorinated quinoxaline unit of TPQ-3F, the OSC devices based on TPQ-3F:Y6:m-DBDF obtained the best power conversion efficiency (PCE) of 15.71% compared with the PCE of the p-DBDF- and o-DBDF-processed devices.