MoS2 Nanoresonators: Intrinsically Better Than Graphene?

Abstract

We perform classical molecular dynamics simulations to examine the intrinsic energy dissipation in single-layer MoS${}_2$ nanoresonators, where a point of emphasis is to compare its dissipation characteristics with those of single-layer graphene. Our key finding is that MoS${}_2$ nanoresonators exhibit significantly lower energy dissipation, and thus higher quality (Q)-factors by at least a factor of four below room temperature, than graphene. Furthermore, this high Q-factor endows MoS${}_2$ nanoresonators with a higher figure of merit, defined as frequency times Q-factor, despite a resonant frequency that is $50$ smaller than graphene for the same size. By utilizing arguments from phonon-phonon scattering theory, we show that this reduced energy dissipation is enabled by the large energy gap in the phonon dispersion of MoS${}_2$, which separates the acoustic phonon branches from the optical phonon branches, leading to a preserving mechanism for the resonant oscillation of MoS${}_2$ nanoresonators. We further investigate the effects of tensile mechanical strain and nonlinear actuation on the Q-factors, where the tensile strain is found to counteract the reductions in Q-factor that occur with higher actuation amplitudes. Overall, our simulations illustrate the potential utility of MoS${}_2$ for high frequency sensing and actuation applications.

Nanoscale, published

References in corpus (6)

• The phonon dispersion of graphite by inelastic x-ray scattering
• Young's modulus of Graphene: a molecular dynamics study
• The Importance of Edge Effects on the Intrinsic Loss Mechanisms of Graphene Nanoresonators
• Enhancing the Mass Sensitivity of Graphene Nanoresonators Via Nonlinear Oscillations: The Effective Strain Mechanism
• Elastic and non-linear stiffness of graphene: a simple approach
• Intrinsic Energy Dissipation in CVD-Grown Graphene Nanoresonators

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• Theory of substrate-directed heat dissipation for single-layer graphene and other two-dimensional crystals
• The Buckling of Single-Layer MoS2 Under Uniaxial Compression
• Time-domain response of atomically thin $\mathrm{Mo}{\mathrm{S}}_2$ nanomechanical resonators
• Mechanical Strain Effects on Black Phosphorus Nanoresonators
• A Fast Uniaxial Compression of the Single-Layer MoS2