Functionalization effect on the electronic properties of single walled carbon nanotubes

Abstract

OH-functionalized single-walled carbon nanotubes (SWNTs), i.e. SWNT-OH, were prepared through the ball-milling of purified SWNTs with KOH. The composition of the pristine SWNTs bulk sample was characterized by resonance Raman scattering. The OH-functionalization-induced shrinking of the energy gap, the charge transfer from C to -OH, the depletion of top valence band density, the modification of energy band structure and the significant reduction in the work function of SWNTs were experimentally studied by variable temperature FTIR, Raman scattering, ultra-violet photoelectron spectroscopy, X-ray photoelectron energy loss spectroscopy etc. Ab initio calculation was also performed to assist the discussion. © 2008 World Scientific Publishing Company.