2D hybrid bilayer crystals as a playground for chirality

This project aims to create new atomically thin solids built from discrete 2D molecular architectures that are a few nanometers thick with their symmetry and lattice periodicity tuned over a long range. These characteristics are currently impossible to achieve in conventional covalent crystalline solids due to the sensitivity of their bonds to defects. We will use aligned vertical heterostructures of these ultrathin solids to create a chiral platform with electronic and optical properties tunable down to the molecular scale. This capitalizes on the flexibility in choosing the organic molecular entities, and our ability to stack these materials in different combinations and orientations. We have demonstrated large-scale optically anisotropic perylene based 2D molecular architectures on top of monolayer transition metal dichalcogenide crystals to create four atom thick hybrid bilayer crystals (HBCs). HBCs exhibit fully anisotropic photoluminescence from excitons whose properties are tunable through the molecular geometry, highlighting their potential in optoelectronics. Given the control over the crystallinity, these materials are also a promising platform for studying emergent phenomena such as chirality. By accessing the electronic states and the nature of the hybridization in this new material system, we can then reveal the extent of tunability and practicality of integrating these chiral solids into solid state devices.