Chemical doping of individual semiconducting carbon-nanotube ropes
We report the effects of potassium doping on the conductance of individual semiconducting single-walled carbon nanotube ropes. We are able to control the level of doping by reversibly intercalating and de-intercalating potassium. Potassium doping changes the carriers in the ropes from holes to electrons. Typical values for the carrier density are found to be ∼100–1000 electrons/μm. The effective mobility for the electrons is μeff∼20–60 cm2 V-1 s-1, a value similar to that reported for the hole effective mobility in nanotubes [R. Martel et al., Appl. Phys. Lett. 73, 2447 (1998)].
Additional Information© 2000 The American Physical Society. Received 1 November 1999. We would like to thank Steven G. Louie and Marvin Cohen for helpful discussions, and G.Y. McLean for experimental assistance. This work was supported by D.O.E. (Basic Energy Sciences, Materials Sciences Division, the sp2 Materials Initiative). Nanotube production at Rice University was supported by the Office of Naval Research, the Robert A. Welch Foundation, and the Texas Advanced Technology Program.
Published - BOCprb00.pdf