Anisotropic electronic, mechanical, and optical properties of monolayer WTe2
Author
Torun, E.
Sahin, H.
Cahangirov, S.
Rubio, A.
Peeters, F. M.
Date
2016Source Title
Journal of Applied Physics
Print ISSN
0021-8979
Publisher
American Institute of Physics Inc.
Volume
119
Issue
7
Pages
074307-1 - 074307-7
Language
English
Type
ArticleItem Usage Stats
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Abstract
Using first-principles calculations, we investigate the electronic, mechanical, and optical properties of monolayer WTe2. Atomic structure and ground state properties of monolayer WTe2 (Td phase) are anisotropic which are in contrast to similar monolayer crystals of transition metal dichalcogenides, such as MoS2, WS2, MoSe2, WSe2, and MoTe2, which crystallize in the H-phase. We find that the Poisson ratio and the in-plane stiffness is direction dependent due to the symmetry breaking induced by the dimerization of the W atoms along one of the lattice directions of the compound. Since the semimetallic behavior of the Td phase originates from this W-W interaction (along the a crystallographic direction), tensile strain along the dimer direction leads to a semimetal to semiconductor transition after 1% strain. By solving the Bethe-Salpeter equation on top of single shot G0W0 calculations, we predict that the absorption spectrum of Td-WTe2 monolayer is strongly direction dependent and tunable by tensile strain.
Keywords
Absorption spectroscopyAnisotropy
Calculations
Crystal atomic structure
Crystal structure
Ground state
Monolayers
Optical properties
Transition metals
Tungsten compounds
Bethe-Salpeter equation
Crystallographic directions
First-principles calculation
Ground state properties
In-plane stiffness
Monolayer crystals
Semiconductor transition
Transition metal dichalcogenides
Tensile strain