Electronic and optical properties of nitrogen-doped multiwalled carbon nanotubes

Abstract

Highly nitrogen-doped carbon nanotube (CNx NT, x=12 at. %) was synthesized by the pyrolysis of acetonitrile on Co-Mo catalysts. The electronic structures and chemical bondings of CNx NT were studied using various spectroscopic techniques: Raman, photoelectron and x-ray absorption spectroscopies. The ultrafast pump-probe measurements of CNx NT exhibited a larger third-order susceptibility χ(3), a relaxation time of τ2 =1 ps and improved saturable absorption, as compared with undoped multiple-walled carbon nanotubes, which indicate that N-doping can improve all-optical switching properties of carbon nanotubes. © 2006 The American Physical Society.