Mapping Modified Electronic Levels in the Moiré Patterns in MoS 2 /WSe 2 Using Low-Loss EELS.

Autor: Susarla S; Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States.; Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Orsay 91405, France., M Sassi L; Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States., Zobelli A; Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Orsay 91405, France., Woo SY; Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Orsay 91405, France., Tizei LHG; Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Orsay 91405, France., Stéphan O; Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Orsay 91405, France., Ajayan PM; Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States.
Jazyk: angličtina
Zdroj: Nano letters [Nano Lett] 2021 May 12; Vol. 21 (9), pp. 4071-4077. Date of Electronic Publication: 2021 Apr 26.
DOI: 10.1021/acs.nanolett.1c00984
Abstrakt: Hybrid/moiré interlayer and intralayer excitons have been realized in twisted two-dimensional transition metal chalcogenides (2D-TMD) due to variation in local moiré potential within a moiré supercell. Though moiré excitons have been detected in TMD heterostructures by macroscopic spectroscopic techniques, their spatial distribution is experimentally unknown. In the present work, using high-resolution scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS), we explore the effect of the twist angle in MoS 2 /WSe 2 heterostructures. We observe weak interaction between the layers at higher twist angles (>5°) and stronger interaction for lower twist angles. The optical response of the heterostructure varies within the moiré supercell, with a lower energy absorption peak appearing in regions with the AA stacking.
Databáze: MEDLINE
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