Multi‐Field Coupling in Organic Charge Transfer Cocrystals: Rational Design and Emerging Opto‐Electro‐Magnetic Functions

ABSTRACT Organic charge‐transfer (CT) cocrystals consist of periodically arranged electron donor (D) and acceptor (A) molecules. Intermolecular interactions in such systems reshape electronic configurations and create emergent states unavailable to isolated molecules, granting CT cocrystals unique optical, electrical, and magnetic properties. While recent years have witnessed substantial progress in this field, the fundamental mechanisms underlying their optoelectronic and magnetic behaviors, as well as the intrinsic coupling of the three functional properties, remain insufficiently understood at the molecular and charge‐transfer levels. Moreover, the development of CT cocrystals from discrete monomers to complex integrated architectures lacks systematic summarization. This review constructs a structure–property correlation framework for CT cocrystals based on three key factors: energy‐level reconstruction, molecular packing mode, and degree of charge transfer (DCT). Their critical roles in regulating the optoelectronic and magnetic functionalities are elaborated, alongside recent advances in integrated CT‐cocrystal architectures including block heterostructures, branched configurations, and core‐shell structures. This work finally outlines major challenges in multicomponent and high‐order cocrystal design, precise structural and DCT modulation, and multifunctional integration. Future prospects are further presented for CT cocrystals in advanced optoelectronic devices, tunable magnetism, and optoelectromagnetically coupled integrated systems.