Layer‐by‐Layer Processed Efficient All‐Polymer Solar Cells Based on a Nonfused Polymerized Small Molecule Acceptor

Abstract

AbstractThe development of polymer acceptors is of crucial importance for all‐polymer solar cells (all‐PSCs). However, the state‐of‐the‐art polymer acceptors are typically based on Y‐series small molecule acceptors. Their synthetic complexity and high synthesis cost remain a severe challenge for future practical application of organic photovoltaics. Herein, a novel non‐fused polymer acceptor named PDO is synthesized. The all‐PSC achieves a best power conversion efficiency of 9.68% in the layer‐by‐layer (LBL) processed device, which is much better than that (8.14%) of the conventional bulk‐heterojunction device. Comprehensive analysis on the electrical and morphological characterizations reveal that the improved device performance in the LBL‐processed device is originated from efficient exciton extraction and charge transport, suppresses charge recombination, improves molecular ordering, and optimizes active layer morphology. These results validate that the fabrication of all‐PSCs with non‐fused polymerized small molecule acceptors is a promising strategy to develop low‐cost and high‐performance all‐PSCs.