Synthesis, characterization and low field emission of CNx nanotubes

Aligned CNx nanotubes were fabricated by pyrolyzing ethylenediamine on p-type Si(1 1 1) substrates using iron as the catalyst. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrum (XPS) and Raman spectroscopy were used to characterize the CNx nanotubes. The CNx nanotubes with the average length of 20 μm and diameters in the range of 50-100 nm have the “bamboo-like” structure and worse crystalline order. The low-field emission measurements of the CNx nanotubes indicated that 20 μA/cm2 current densities were observed at an electric field of 1.4 V/μm and 1.280 mA/cm2 were obtained at 2.54 V/μm. The CNx nanotubes exhibit better field emission properties than the carbon nanotubes and the BCN nanotubes. The emission mechanism of CNx nanotubes is also discussed.