Organic cocrystals: From high-performance molecular materials to multi-functional applications

Advancements in organic electronics are propelling the development of new material systems, where organic materials stand out for their unique benefits, including tunability and cost-effectiveness. Organic single crystals stand out for their ordered structure and reduced defects, enhancing the understanding of the relationship between structure and performance. Organic cocrystal engineering builds upon these foundations, exploring intermolecular interactions within multicomponent-ordered crystalline materials to combine the inherent advantages of single-component crystals. However, the path to realizing the full potential of organic cocrystals is fraught with challenges, including structural mismatches, unclear cocrystallization mechanisms, and unpredictable property alterations, which complicate the effective cocrystallization between different molecules. To deepen the understanding of this promising area, this review introduces the mechanism of organic cocrystal formation, the various stacking modes, and different growth techniques, and highlights the advancements in cocrystal engineering for multifunctional applications. The goal is to provide comprehensive guidelines for the cocrystal engineering of high-performance molecular materials, thereby expanding the applications of organic cocrystals in the fields of optoelectronics, photothermal energy, and energy storage and conversion. This review provides a comprehensive exploration of organic cocrystal engineering, focusing on the mechanism of cocrystal formation, stacking modes, driving forces behind cocrystal synthesis, innovative growth techniques, and the multifunctional properties of organic cocrystals, which offers guidelines for engineering high-performance molecular materials and expanding the applications of organic cocrystals in optoelectronic, photothermal, and energy storage and conversion fields. image