Alkali Metals Adsorbed on Nanoporous Graphene: Charge Transfer and Metallic Phase

The doping mechanism of fully suspended nanoporous graphene with alkali metals unveils the charge redistribution between the donors and graphene. The evolution of the electronic charge induced in the graphene upper Dirac cone has been correlated with the electron-phonon interaction by employing complementary electronic and vibrational spectroscopic techniques in ultra high vacuum ambient. K and Cs doping induces a significant rigid band shift and Dirac cone filling correlated with the neat formation of a pi*-plasmon mode and a clear signature of electron-phonon interaction in the Raman spectra, while Na doping slightly influences the graphene electronic and vibrational response, fostered by adatom Na clustering.