Work

Giant Modulation of Interlayer Coupling in Twisted Bilayer ReS 2

Year: 2025

Type: article

Abstract: Stacking monolayers of two‐dimensional (2D) transition metal dichalcogenides with different twist angles can provide a way to tune their quantum optical and electronic characteristics. This study demonstrates that the bandgap energy and interlayer coupling strength of twisted bilayer (tBL) ReS 2 can be continuously modulated by the twist angle. By controlling the twist angle between 0° and 10°, the exciton energy of tBL ReS 2 is tuned over a range of 40 meV, which is comparable to the difference between the exciton energies of intrinsic monolayer and bilayer ReS 2 . Such a wide modulation range for the interlayer coupling strength of tBL ReS 2 , which significantly affects the band structure, is also shown by the systematic shift in the low‐and high‐frequency Raman modes and results of a strain study using scanning transmission electron microscopy imaging. Density functional theory calculations on moiré superlattice tBL ReS 2 structures confirm a consistent increase in the bandgap with the twist angle. The strong modulation of interlayer coupling by the twist angle in tBL ReS 2 is attributed to the low symmetry of the 1T ' structure and in‐plane anisotropy of the ReS 2 lattice. These findings demonstrate the enhanced tunability of twist‐controlled electronic structure in anisotropic 2D materials, offering new pathways for designing reconfigurable quantum materials.

Source: Advanced Science

DOI: 10.1002/advs.202500411