Electron-electron interactions and doping dependence of the two-phonon Raman intensity in graphene

By D. Basko, S. Piscanec, Andrea C. Ferrari. 2009

394 citations recorded by the source corpus.

Raman spectroscopy is a fast and nondestructive means to characterize graphene samples. In particular, the Raman spectra are strongly affected by doping. While the resulting change in position and width of the $G$ peak can be explained by the nonadiabatic Kohn anomaly at $\ensuremath{\Gamma}$, the significant doping dependence of the $2D$ peak intensity has not been understood yet. Here we show that this is due to a combination of electron-phonon and electron-electron scattering. Under full resonance, the photogenerated electron-hole pairs can scatter not just with phonons but also with doping-induced electrons or holes, and this changes the intensity. We explain the doping dependence and show how it can be used to determine the corresponding electron-phonon coupling. This is higher than predicted by density-functional theory, as a consequence of renormalization by Coulomb interactions.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/26985175a8886e6ea7009ec77800821f851ab91e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

In Materials Chemistry

Citations in the corpus

Inkjet-printed graphene electronics. (2011, neutral): “doping of at least 10(13)cm (2).(115) 117 We derive η ≈ 1.”
Graphene–silicon phase modulators with gigahertz bandwidth (2017, background): “From the Raman G peak position, Pos(G), full width at half maximum, FWHM(G), and intensity and area ratios of D and G peaks we estimate[35, 36] E F 100meV ( ∼ 200meV) at the longer top (shorter bottom) arms of the MZI.”
Graphene mode-locked ultrafast laser. (2009, background): “1.(34) These give the time of optical phonon emission by the”
Raman Spectroscopic Characterization of Graphene (2010, background): “A 2D peak is the second order of the D peak and caused by the double resonant Raman scattering with two-phonon emissions ( 52 , 57 ).”
Interaction between graphene and copper substrate: The role of lattice orientation (2014, background): “FWHM(2D) increases and I(2D) decreases upon both p- and n-doping mainly due to electronelectron interactions, and also electron-phonon coupling strength (expressed as a dimensionless parameter λ), which increases to a small extent upon doping [62, 65].”
Transfer of CVD-grown monolayer graphene onto arbitrary substrates. (2011, background): “with the increase of the integrated 2D to G intensity ratio describedabove.(54,55)Wealsonote that the increaseof the”