Tunable electron phonon interaction in MoS$_{2}$*

Transition metal dichalcogenides such as MoS$_{2}$ are of current interest for optoelectronic application, but also for studying fundamental aspects of light-matter interaction and excitonic properties in strictly two-dimensional semiconductors. We explore the impact of the charge carrier density on the electron phonon interaction strength by non-resonant and resonant Raman spectroscopy. We utilize MoS$_{2}$ field effect structures with polymer electrolyte gate facilitating a change of the 2D electron density by more than two orders of magnitude [1]. We report unusual behavior in polarization and charge carrier dependent resonant Raman spectra that point towards strong electron-phonon coupling in MoS$_{2}$ and the importance of excitonic phenomena.\newline [1] Miller et al., APL 106, 122103 (2015).