Growth of Diameter-Controlled Carbon Nanotubes via a Modified Catalytic Layer

We investigated the relationship between carbon nanotube (CNT) diameters and catalytic layer formation by adjusting the thickness of a Fe catalytic layer on a geometrically-modified Al2O3 underlying layer. Measurements of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy consistently revealed that the Al2O3 layer is more a suitable supportive layer for obtaining CNTs with small diameters. Further, the diameters of the CNTs are proportional to the thickness of the Fe catalytic layer. A systematic study using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) was performed to elucidate the diameter-controlling process related to the formation of the catalytic layer. In addition, the field emission characteristics of two representative CNTs were evaluated to determine the relationship between the CNT diameter and the field emission performance. KCI Citation Count: 6