Intralayer-Mediated Vertical Assembly of Two-Dimensional Organic Molecular Crystals toward Three-Dimensional...

Two-dimensional organic vertical heterostructures (2D OVHs) from small molecules offer a molecularly programmable pathway toward three-dimensional integration in next-generation optoelectronics. However, the vertical assembly of 2D crystals remains challenging due to the limited control over the interfacial alignment in stacked bilayers. Here, we propose an intralayer-mediated vertical assembly strategy to synthesize 2D OVHs with oriented interfacial alignment. The designable in-plane molecular arrangement facilitated lattice matching of stacked 2D crystals, which suppresses the disordered nucleation and island epitaxial growth. Owing to the tailorable nucleation sequence of the vertical assembly method, the spatial organization of components in OVHs can be reversed, ultimately promoting the synthesis of OVHs from bilayer stacked to multilayer stacked structures. The resulting OVHs exhibit both in-plane optical waveguide and out-of-plane photon conversion capabilities, demonstrating their potential in three-dimensional photonics applications. Therefore, the multichannel polarization-related optical logics were achieved based on the obtained OVHs. This strategy applies to other polycyclic aromatic hydrocarbon (PAH) molecules, thus providing a molecular-level predictive pathway for creating three-dimensional integrated devices.