Development and applications of epitaxial heterostructures based on organic nanowires

One-dimensional organic single crystals offer a promising platform for miniaturized photonics, yet their single-component nanowire forms currently lack the functional complexity required for integrated devices. In this review, the systems discussed are described as multicomponent or hierarchical organic nanowire heterostructures with spatially controlled composition, interfaces, topology, and functions. We categorize hierarchical designs into axial, radial, and branch topologies, and discuss the critical roles of noncovalent interactions, lattice engineering, kinetic control, and supramolecular assembly in achieving precise spatial division and high-quality interfaces. We further summarize device-level demonstrations enabled by these heterostructures, including optical anti-counterfeiting, photonic barcoding, exciton cascade control, and logic-like signal processing. Finally, we identify predictive growth and high-density integration as key challenges, and outline strategies toward building programmable, highly integrated organic photonic chips from reproducible low-dimensional modules.