The intrinsic temperature-dependent Raman spectra of graphite in the temperature range from 4K to 1000K

Temperature-dependent (T-dependent) Raman scattering can provide valuable informations on thermal properties, phonon anharmonicity and electron-phonon coupling of graphene-based materials. Graphene are found to exhibit extrinsic T-dependent Raman behavior at low temperature in vacuum or N-2 gas, showing a behavior of heavily doped graphene. To obtain intrinsic properties of graphene-based materials, we focused on the comparative T-dependent Raman study on graphite and silicon in the temperature range of 4 K similar to 1000 K by different excitation lasers and different hot-stages or cryogenic stations. In contrast to the monotonic increase of full width at half maximum (FWHM) with temperature for the Si mode in silicon, FWHM for the G mode in graphite exhibits a minimum when T similar to 700K, which can be explained by the contributions from phonon anharmonicity and electron-phonon coupling. The result shows that the previous theoretical works underestimate the contribution from phonon anharmonicity above similar to 600 K. The electron-phonon coupling strength of 0.026 is revealed, smaller than that of graphene. The peak position of G peak of graphite shows a nonlinear decrease with increasing temperature, which agrees well with the previous theoretical calculation. Our results find that the contribution of phonon anharmonicity to both peak position and FWHM is more prominent for the G mode in graphite than the Si mode in silicon. (C) 2019 Elsevier Ltd. All rights reserved.