Utilizing Ternary Strategy to Reduce the Influence of Polymer Batch‐to‐Batch Variation in Organic Solar Cells

Despite producing the best device performances, several major issues such as the batch-to-batch variation and low molecular weight (M-w) optimization greatly hinder the progress for the organic solar cells. Herein, tetraphenylethylene (TPE) as a third component has been added in a series of PM6:Y6 blends with different donor molecular weights (42-129 kDa). Ultimately, ternary devices fabricated by the PM6 with about half the M-w (66 and 74 kDa) of the standard donor (129 kDa) produce an excellent power conversion efficiency (PCE) of 15.09% and 15.15% owing to enhanced morphology and charge mobility, as compared to a standard binary PCE of 15.65%, respectively, indicating the possibility of attaining high-performance attributes from low M-w polymers. Furthermore, the TPE inclusion in the 129 kDa binary blend leads to a remarkable PCE of 16.48%. This strategy, therefore, illustrates a relatively simple approach to overcome the batch-to-batch variation problem associated with polymers for organic solar cells.