Molecular‐Template Vertical Epitaxial Growth of 2D Stacked Organic Cocrystal

Abstract 2D organic stacked heterostructures (2D OSHs) have become an ideal material for developing on‐chip integrated optoelectronic devices due to their unique interlayer coupling effects and interface engineering potentials. However, achieving a controlled synthesis of 2D OSHs remains challenging due to the inherent difficulty of regulating organic molecular orientations and overcoming thermodynamic barriers. Herein, a cocrystal engineering‐based template method is reported, where cocrystals are engineered into 2D templates to induce vertical epitaxial growth of other cocrystals, enabling the large‐scale synthesis of 2D OSHs. The thickness ratio of two layers can be precisely regulated and exhibits a continuously tunable emission from yellow to blue, where the OSHs with the ratio of 0.25 exhibit near‐white emission (CIE: 0.33, 0.35). In addition, the OSHs exhibit excellent dual‐band optical waveguide performance. This work provides a new synthesis method for OSH's functional integrated materials in the fields of optical displays and waveguides, promoting their application in the next generation of integrated optoelectronic devices.