Year: 2014
Type: article
Abstract: We perform classical molecular dynamics simulations to examine the intrinsic energy dissipation in single-layer MoS2 nanoresonators, where the point of emphasis is to compare their dissipation characteristics with those of single-layer graphene. Our key finding is that MoS2 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 MoS2 nanoresonators with a higher figure of merit, defined as frequency times Q-factor, despite a resonant frequency that is 50% smaller than that of graphene of 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 MoS2, which separates the acoustic phonon branches from the optical phonon branches, leading to a preserving mechanism for the resonant oscillation of MoS2 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 MoS2 for high frequency sensing and actuation applications.
Source: Nanoscale
DOI: 10.1039/c3nr05991j
Authors: Jin-Wu Jiang, Harold S. Park, Timon Rabczuk
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W2172071820