The morphological effect on electronic structure and electrical transport properties of one-dimensional carbon nanostructures

Aligned one-dimensional carbon nanostructures with different morphologies such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs) have been synthesized by the plasma-enhanced chemical vapor deposition method with different catalyst/underlayer combinations. The electronic structures of CNTs and CNFs have been studied by X-ray absorption near-edge structure spectroscopy (XANES), which reveals that CNTs have much fewer oxidized groups than CNFs. Moreover, the electrical transport properties of a single CNT or CNF have been measured in situ under transmission electron microscopy observation and the results show that CNTs have 2 orders lower resistivity than that of CNFs. A single CNT can be applied with higher voltage and larger current before thermal breakdown compared to a single CNF, which can be related to the electronic structure as revealed by XANES. Our results offer a good example of examining the relationship between morphological structure, electronic structure and electrical transport properties in carbon nanomaterials, which will certainly be useful in the applications of nano-devices.