title: Doping in carbon nanotubes probed by Raman and transport measurements.
abstract: In situ Raman experiments together with transport measurements have been carried out on carbon nanotubes as a function of gate voltage. In metallic tubes, a large increase in the Raman frequency of the G(-) band, accompanied by a substantial decrease of its linewidth, is observed with electron or hole doping. In addition, we see an increase in the Raman frequency of the G(+) band in semiconducting tubes. These results are quantitatively explained using ab initio calculations that take into account effects beyond the adiabatic approximation. Our results imply that Raman spectroscopy can be used as an accurate measure of the doping of both metallic and semiconducting nanotubes.
authors.affiliation: Department of Physics, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Anindya
authors.initials: A
authors.lastname: Das
authors.forename: A K
authors.initials: AK
authors.lastname: Sood
authors.forename: A
authors.initials: A
authors.lastname: Govindaraj
authors.forename: A Marco
authors.initials: AM
authors.lastname: Saitta
authors.forename: Michele
authors.initials: M
authors.lastname: Lazzeri
authors.forename: Francesco
authors.initials: F
authors.lastname: Mauri
authors.forename: C N R
authors.initials: CN
authors.lastname: Rao