Yoon Sang Won, Kim Shin Young, Park Jeunghee, Park Chan Jun, Lee Cheol Jin
Department of Chemistry, Korea University, Jochiwon 339-700, Korea.
J Phys Chem B. 2005 Nov 3;109(43):20403-6. doi: 10.1021/jp0546305.
The electronic structure of multiwalled carbon nanotubes (CNTs) has been investigated, depending on the growth temperature, using synchrotron X-ray photoelectron spectroscopy (XPS) and field emission measurements. The vertically aligned CNTs are grown via pyrolysis of ferrocene and acetylene in a broad temperature range 600-1000 degrees C. The CNTs have a cylindrical structure with a uniform diameter of 20 nm. As growth temperature increases, due to an improved crystallinity of the graphitic sheets, the width of the XPS C 1s peak becomes narrower and the intensity of the valence band increases. Field emission from the as-grown CNTs exhibits a large enhancement of current density with growth temperature, strongly correlated with the electronic structure revealed by XPS.
利用同步辐射X射线光电子能谱（XPS）和场发射测量，研究了多壁碳纳米管（CNT）的电子结构与生长温度的关系。垂直排列的碳纳米管是通过二茂铁和乙炔在600-1000℃的宽温度范围内热解生长的。碳纳米管具有直径为20nm的均匀圆柱形结构。随着生长温度的升高，由于石墨片层结晶度的提高，XPS C 1s峰的宽度变窄，价带强度增加。生长态碳纳米管的场发射显示出电流密度随生长温度的大幅增强，这与XPS揭示的电子结构密切相关。
