Probing carbon isotope effects on the Raman spectra of graphene with different [superscript 13]C concentrations

A resonance Raman study of graphene samples with different [superscript 13]C isotopic concentrations and using different laser excitation energies is presented. The main Raman peaks (D, G, G[superscript *], and 2D) of graphene were measured and the dependence of their frequencies on the isotope atom...

Full description

Bibliographic Details
Main Authors: Carvalho, Bruno R., Hao, Yufeng, Righi, Ariete, Colombo, Luigi, Ruoff, Rodney S., Pimenta, Marcos A., Fantini, Cristiano, Rodriguez Nieva, Joaquin Fran
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society 2015
Online Access:http://hdl.handle.net/1721.1/98418
https://orcid.org/0000-0002-3023-396X
Description
Summary:A resonance Raman study of graphene samples with different [superscript 13]C isotopic concentrations and using different laser excitation energies is presented. The main Raman peaks (D, G, G[superscript *], and 2D) of graphene were measured and the dependence of their frequencies on the isotope atomic mass follows a simple harmonic oscillator relation. The G[superscript *] and 2D double-resonance peak positions were measured as a function of the laser energy, and we observed that the slopes of the laser energy dependence are the same independently of isotope concentration. This result shows that isotopic substitution does not alter the electron and phonon dispersions near the K point of the graphene Brillouin zone. From the linewidth of G and 2D Raman peaks, we have also obtained a dependence of the phonon lifetime on the [superscript 13]C isotope concentration.