High‐Performance Photoactive Polymers: Innovations in Ternary Polymerization for Solar Applications

Abstract In recent years, polymer solar cells (PSCs) have achieved rapid progress, with power conversion efficiencies (PCEs) reaching up to 20.25%, driven by significant advancements in device fabrication and active‐layer materials. The ternary polymerization strategy has proven to be a straightforward and effective approach for developing high‐performance photoelectric polymers by incorporating a third monomer into the polymer backbone. This incorporation effectively optimizes intrinsic photoelectric properties, including UV–vis absorption, energy levels, solubility, crystallinity, morphology, charge transfer, mechanical robustness, batch‐to‐batch reproducibility, and device stability. This review highlights the latest advancements in the ternary polymerization strategy for designing high‐performance photoactive copolymers (both ternary polymer donors and acceptors), with a particular focus on batch‐to‐batch reproducibility, stability, and potential applications in commercial development. The aim is to provide valuable guidance for the development of high‐performance photoelectric polymer materials using the ternary polymerization strategy.