Complex Strain Scapes in Reconstructed Transition-Metal Dichalcogenide Moiré Superlattices

0571052 - ÚFCH JH 2024 RIV US eng J - Journal Article
Rodríguez Rodríguez, Álvaro - Varillas, Javier - Haider, Golam - Kalbáč, Martin - Frank, Otakar
Complex Strain Scapes in Reconstructed Transition-Metal Dichalcogenide Moiré Superlattices.
ACS Nano. Roč. 17, č. 8 (2023), s. 7787-7796. ISSN 1936-0851. E-ISSN 1936-086X
R&D Projects: GA ČR(CZ) GX20-08633X; GA MŠMT EF16_026/0008382
Grant - others:Ministerstvo školství, mládeže a tělovýchovy - GA MŠk(CZ) CZ.02.1.01/0.0/0.0/16_026/0008382
Institutional support: RVO:61388955
Keywords : Atomic Reconstruction * Moiré Superlattice * Molecular Dynamics * Raman Spectroscopy * Strain * Transition-Metal Dichalcogenide
OECD category: Physical chemistry
Impact factor: 17.1, year: 2022
Method of publishing: Open access

We investigate the intrinsic strain associated with the coupling of twisted MoS2/MoSe2 heterobilayers by combining experiments and molecular dynamics simulations. Our study reveals that small twist angles (between 0 and 2°) give rise to considerable atomic reconstructions, large moiré periodicities, and high levels of local strain (with an average value of ∼1%). Moreover, the formation of moiré superlattices is assisted by specific reconstructions of stacking domains. This process leads to a complex strain distribution characterized by a combined deformation state of uniaxial, biaxial, and shear components. Lattice reconstruction is hindered with larger twist angles (>10°) that produce moiré patterns of small periodicity and negligible strains. Polarization-dependent Raman experiments also evidence the presence of an intricate strain distribution in heterobilayers with near-0° twist angles through the splitting of the E2g1 mode of the top (MoS2) layer due to atomic reconstruction. Detailed analyses of moiré patterns measured by AFM unveil varying degrees of anisotropy in the moiré superlattices due to the heterostrain induced during the stacking of monolayers.
Permanent Link: https://hdl.handle.net/11104/0342363