Product Code: ICA11_N302

Laser-Induced Growth of Diameter-Modulated Single-Walled Carbon Nanotubes
Authors:
M. Mahjouri-Samani, University of Nebraska-Lincoln; Lincoln NE
Y.S. Zhou, University of Nebraska-Lincoln; Lincoln NE
W. Xiong, University of Nebraska-Lincoln; Lincoln NE
M. Mitchell, University of Nebraska-Lincoln; Lincoln NE
Y.F. Lu, University of Nebraska - Lincoln; Lincoln NE USA
Presented at ICALEO 2011

Periodic diameter modulation of individual carbon nanotubes (CNTs) by rapid temperature variation in laser-assisted chemical vapor deposition (LCVD) process was successfully achieved. A CO2 laser was used to quickly and precisely modulate the growth temperature. Due to inverse relationship between the diameter of SWNTs and the growth temperature, tapered and diameter-alternating tubes were grown by modulating the CO¬2 laser power during the growth. The diameter-modulated SWNTs were grown across a pair of Mo electrodes to form field-effect transistors (FETs) for investigation of their electrical and optical properties. Variations in the bandgap of the individual semiconducting SWNTs were detected meaning the formation of multi bandgaps within a single tube. Transmission electron microscopy and Raman spectroscopy were also studied to investigate the structural and electronic properties of the structures.