Phonon scattering processes in molybdenum disulfide

Compared with graphene, 2H-MoS ₂ possesses a non-zero bandgap and thus has an unlimited potential for electronic, spintronic, and optoelectronic applications. Understanding of the phonon scattering mechanisms is crucial to its device applications because the heat flow and transport are the basic processes functioning at various temperatures. So far, the knowledge of the phonon anharmonicity of 2H-MoS ₂ is limited due to the availability from a narrow temperature range and the absence of the low frequency phonon information. Here, we report an experimental study on the temperature dependence of the frequency and linewidth of 2H-MoS ₂ by Raman scattering over a wide temperature range from 2.2 to 1000 K and down to the wavenumber of 10 cm ^-1 . The cubic anharmonicity is found to be dominant at low temperatures, and quartic anharmonicity predominates at high temperatures. The obtained shear mode seems insensitive to the anharmonic effects. The damping effects are discussed based on the available experimental data. These phonon scattering behaviors of 2H-MoS ₂ are of great help to the future nanodevice developments and applications.