Staged Orientation‐Controlled Epitaxy of Organic Low‐Dimensional Heterostructures

ABSTRACT Organic low‐dimensional heterostructures (OLDHs) possess remarkable optoelectronic properties, positioning them as candidates for next‐generation optoelectronic integrated systems. While epitaxial self‐assembly enables efficient preparation, ensuring precise orientation during heteroepitaxial growth remains a fundamental challenge. Herein, a staged orientation controlled epitaxial growth strategy is developed to obtain OLDHs composed of two 4H‐Cyclopenta[2,1‐b:3,4‐b']dithiophene (CDT)‐based cocrystals. Importantly, each epitaxy stage is governed by in‐plane molecular spacing matching relationships between multiple crystal‐plane combinations, which allows for the controllable relative position and continuously adjustable epitaxy‐length of axial/lateral OLDHs by regulating the material ratio ( R = n CB / n CQ ) of the heterogenous components. The fabricated OLDHs exhibit promising functionalities as optical filters and multi‐channel optical routing by exploiting energy transfer and photon propagation within the heterostructures. This strategy provides a crucial pathway for controllable epitaxial self‐assembly, thereby shedding light on the synthesis methodology of OLDHs.