Evidence of Purely Electronic Lattice at Interface of TMD/Bi₂Se₃ 2D Heterostructures Induced by Strong Interlayer Coupling

Vertically-stacked 2D heterostructures are more than a sum of the individual layers, but a product of the interlayer coupling and twist angle. New properties emerge from interlayer orbital interactions and charge redistribution, further modulated by the interlayer atomic registry and moiré superlattice. This talk shows experimental and theoretical indications of a real-space, non-atomic lattice formed by significant charge redistribution in vertically stacked Bi₂Se₃/Transition Metal Dichalcogenide (TMD) 2D heterostructures. High-energy (200keV) selected area electron diffraction (SAED) patterns correspond excellently with simulations from the moiré superlattices, suggesting substantial charge redistribution at sites of high interlayer atomic registry. Density functional theory (DFT) predicts concentrated charge pools reside in the interlayer region, located at sites of high nearest-neighbor atomic registry, suggesting the non-atomic lattices are standalone, reside in the interlayer region, and are purely electronic.

References:
[1] Nanoscale, 2019,11, 15929-15938. doi: 10.1039/C9NR04412D
[2] ACS Appl. Mater. Interfaces 2019, 11, 17, 15913-15921. doi: 10.1021/acsami.9b02929