Generalized Assembly of Semiconductor–Molecule Superlattices

The synthesis of structurally precise materials that combine diverse building blocks will accelerate the development of artificial solids for electronics, energy, and medicine. Here, we utilize simulation to identify how organic molecules can self-assemble with 2D materials into periodic superlattices with alternating layers of molecules and 2D monolayers. We experimentally demonstrate the generalizability of this mechanism by applying it to 2D semiconductors and various organic molecules or polymers. The resulting superlattices have unique and well-defined lattice constants that depend on the dimensions of the organic species. We are able to design superlattices with a wide variety of molecules (photoresponsive, chelating, light-emitting moieties), suggesting that the self-assembly does not depend on any specific chemical interaction and yet can accommodate chemically diverse functional groups. We also observe that the 2D materials within the superlattices (MoS2, WSe2) remain quantum-confined, even though the superlattice retains excellent electrical conductivity. This introduction of a mechanism and its experimental realization yield a general design strategy for a large class of quantum-confined, molecule–2D hybrid materials.