High-Performance Small Molecule via Tailoring Intermolecular Interactions and its Application in Large-Area Organic Photovoltaic Modules

Solution-processed organic solar cells are promising owing to their light weight, ease of processability, low cost, flexibility, and large-area fabrication. Particularly, small-molecule active materials have been recently developed using straightforward synthesizing methods, exhibiting the least batch-to-batch variation in physical and optoelectronic properties and highly reproducible efficiency. A series of 2D-BDT-based active materials with various numbers of benzodithiophene (BDT) units and how the number of 2D-BDT units influences the construction of a well-defined interconnected structure are reported. The systematically controlled morphology of the 2D-BDT material helps achieve a high power-conversion efficiency (PCE) of 8.56% and a high fill factor of 0.73 without the use of additives. The reduced charge recombination and well-constructed morphology of this material facilitate a PCE of 7.45% in a 77.8 cm(2) rigid module, which is the outstanding performance in large-area modules.