Phonons in potassium doped graphene: the effects of electron-phonon interactions, dimensionality and ad-atom ordering

Abstract

Graphene phonons are measured as a function of electron doping via the addition of potassium adatoms. In the low doping regime, the in-plane carbon G-peak hardens and narrows with increasing doping, analogous to the trend seen in graphene doped via the field-effect. At high dopings, beyond those accessible by the field-effect, the G-peak strongly softens and broadens. This is interpreted as a dynamic, non-adiabatic renormalization of the phonon self-energy. At dopings between the light and heavily doped regimes, we find a robust inhomogeneous phase where the potassium coverage is segregated into regions of high and low density. The phonon energies, linewidths and tunability are remarkably similar for 1-4 layer graphene, but significantly different to doped bulk graphite.

Accepted in Phys. Rev. B as a Rapid Communication. 5 pages, 3 figures, revised text with additional data

References in corpus (17)

• The electronic properties of graphene
• The Raman Fingerprint of Graphene
• Graphene: Status and Prospects
• Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering
• Electric Field Effect Tuning of Electron-Phonon Coupling in Graphene
• Non-adiabatic Kohn-anomaly in a doped graphene monolayer
• Electron-electron interactions and doping dependence of the two-phonon Raman intensity in graphene
• Accessing the transport properties of graphene and its multi-layers at high carrier density
• Adiabatic and non-adiabatic phonon dispersion in a Wannier function approach
• Doped graphene as tunable electron-phonon coupling material
• Electron-phonon coupling in potassium-doped graphene: Angle-resolved photoemission spectroscopy
• Giant non-adiabatic effects in layer metals: Raman spectra of intercalated graphite explained
• Electronic structure of superconducting KC${}_8$ and non-superconducting LiC${}_6$ graphite intercalation compounds: Evidence for a graphene-sheet-driven superconducting state
• Non-adiabatic phonons within the doped graphene layers of XC${}_6$ compounds
• Probing the electron-phonon coupling in ozone-doped graphene by Raman spectroscopy
• Neutron scattering study of the high energy graphitic phonons in superconducting CaC${}_6$
• Raman signature of electron-electron correlation in chemically doped few-layer graphene

Cited by in corpus (14)

• Anomalous Raman Spectra and Thickness Dependent Electronic properties of WSe2
• Novel highly conductive and transparent graphene based conductors
• Raman Spectroscopy of Electrochemically-Gated Graphene Transistors: Geometrical Capacitance, Electron-Phonon, Electron-Electron, and Electron-Defect Scattering
• Manifestation of charged and strained graphene layers in the Raman response of graphite intercalation compounds
• Superconductivity in graphite intercalation compounds
• On adatomic-configuration-mediated correlation between electrotransport and electrochemical properties of graphene
• Raman response of Stage-1 graphite intercalation compounds revisited
• Nonadiabatic coupling effects in MgB${}_2$ reexamined
• Incidence of multilayers in chemically exfoliated graphene
• Ultralong spin lifetime in light alkali atom doped graphene
• Theoretical Investigation of Two-Dimensional Superconductivity in Intercalated Graphene Layers
• Electron-mediated anharmonicity and its role in the Raman spectrum of graphene
• Tuning Conductivity and Spin Dynamics in Few-Layer Graphene via In Situ Potassium Exposure
• Na-intercalation compounds and Na-ion batteries