Two-dimensional MoS${}_2$ electromechanical actuators

Abstract

We investigate electromechanical properties of two-dimensional MoS${}_2$ monolayers in the 1H, 1T, and 1T${}^{\prime }$ structures as a function of charge doping by using density functional theory. We find isotropic elastic moduli in the 1H and 1T structures, while the 1T${}^{\prime }$ structure exhibits an anisotropic elastic modulus. Moreover, the 1T structure is shown to have a negative Poisson's ratio, while Poisson's ratios of the 1H and 1T${}^{\prime }$ are positive. By charge doping, the monolayer MoS${}_2$ shows a reversibly strain and work density per cycle ranging from -0.68% to 2.67% and from 4.4 to 36.9 MJ/m${}^3$, respectively, making them suitable for applications in electromechanical actuators. Stress generated is also examined in this work and we find that 1T and 1T${}^{\prime }$ MoS${}_2$ monolayers relatively have better performance than 1H MoS${}_2$ monolayer. We argue that such excellent electromechanical performance originate from the electrical conductivity of the metallic 1T and semimetallic 1T${}^{\prime }$ structures high Young's modulus of about $150-200$ GPa.

12 pages, 6 figures

References in corpus (5)

• Elastic properties of freely suspended MoS2 nanosheets
• Auxetic Black Phosphorus: A 2D Material with Negative Poisson's Ratio
• Negative Poisson's Ratio in Single-Layer Graphene Ribbons
• Intrinsic strength and failure behaviors of ultra-small single-walled carbon nanotubes
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Cited by in corpus (2)

• Strain Driven Anomalous Anisotropic Enhancement in the Thermoelectric Performance of monolayer MoS${}_2$
• Molecular potentials for 2D molybdenum disulphide: transferability and performance