Subject Listing - Physics/Astronomy
Advisor: Dr. Weijie Lu
Thursday, Oral Session 3, Presentation 4, Robinson Hall 217
A STUDY ON GROWTH OF CARBON NANOTUBES FROM SILICON CARBIDE
In this experiment silicon carbide substrates were annealed at 1500, 1700, and 1800 °C in a vacuum of 10-5 Torr. X-Ray Photoelectron Spectroscopy (XPS) has been used to investigate the surface products from a reaction of SiC with oxygen, and the surface chemical state of the annealed substrate. Carbon and oxygen were the only elements observed. Carbon nanotubes as a graphite peak were detected at 284.6 eV. Three oxygen species were detected. The C-O and C=O groups are formed due to the exposure to air. The third oxygen peak at 530.1 eV was investigated by angle resolved XPS technique, indicating that oxygen exists in the bulk of CNTs. It was found that oxygen strongly interacts with CNTs at 1700 °C, at the optimum CNT growth temperature. The low oxygen concentration in the vacuum plays an important role in CNT growth on SiC.
Advisor: Dr. Weijie Lu, Research Associate Professor, Surface Science Group, Department of Physics, Fisk University, Nashville, TN