Interfacial polarity-driven self-assembly of organic core/shell heterostructures with directional Fabry–Pérot resonance

Organic core/shell heterostructures (OCSHs) can exhibit diverse optical functionalities through molecular-scale energy-level modulation and interface engineering. However, the construction of structurally well-defined, optically responsive OCSHs with ordered interfaces remains a significant challenge. Here, we proposed an interfacial polarity-driven self-assembly strategy to achieve the directional construction of OCSHs comprising a charge-transfer (CT) cocrystal core and an alloy shell. Selective interfacial complexation and polarity-driven molecular coupling were achieved by sequentially introducing CT cocrystals with gradient intermolecular interaction strengths, thereby disrupting the intrinsic growth pathway of the core and triggering directional alloying of the shell. The resulting OCSHs exhibit highly ordered Fabry-Pérot (FP) cavity modes and orientation-dependent emission, enabling multistate optical logic encoding. Moreover, the approach exhibits broad applicability across multiple CT pairs, affording structurally integrated heterostructures with tunable dual-emission profiles and potential for white-light emission. This work provides a robust framework for constructing hierarchical organic photonic architectures and programmable light-manipulation systems <i>via</i> interfacial interaction engineering.