Abstract
Using resonant Raman scattering spectroscopy with 25 different laser lines, we describe the Raman scattering spectra of monolayer and multilayer 2H-molybdenum diselenide as well as the different resonances affecting the most pronounced features. For high-energy phonons, both - and -symmetry type phonons present resonances with and excitons of together with a marked increase of intensity when exciting at higher energy, close to the -exciton energy. We observe symmetry-dependent exciton-phonon coupling affecting mainly the low-energy rigid layer phonon modes. The shear mode for multilayer displays a pronounced resonance with the exciton while the breathing mode has an intensity that grows with the excitation laser energy, indicating a resonance with electronic excitations at energies higher than that of the exciton.
2 More- Received 5 November 2015
DOI:https://doi.org/10.1103/PhysRevB.93.155407
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