Coordination‐Induced Dispersion of Covalent Organic Frameworks for Organic Solar Cells With 21.03% Efficiency

ABSTRACT

Covalent organic frameworks (COFs) offer modular architectures and ordered π‐channels ideal for organic solar cells (OSCs), yet their integration is hindered by poor solubility and deficient film‐forming rheology. Herein, a coordination‐induced dispersion strategy is reported using vanadium ions to unlock the potential of COFs as high‐performance hole transport layers (HTLs). By intercalating vanadium ions into a novel COF (TBpy), the metal centers act as “molecular wedges,” increasing interlayer spacing to transform the rigid framework into a highly dispersible, solution‐processable precursor. This coordination refines film morphology and fine‐tunes the electronic structure, establishing a seamless cascaded energy alignment. Consequently, OSCs utilizing TBpy‐V HTLs achieve a high power conversion efficiency of 21.03% and extraordinary durability ( T ₈₀ lifetime of 20,097 h). Notably, the high conductivity of the framework renders the device thickness‐insensitive, maintaining 17.80% PCE at 75 nm—a critical advantage for large‐scale manufacturing. This study establishes metal‐ion intercalation as a versatile tool for optimizing both the processability and electronic dynamics of crystalline optoelectronic materials.