Fabrication of CNx nanotubes films using different nitrogen sources and their low field emission properties

The CNx nanotube films have been fabricated on Si substrates by thermal decomposition when NH4Cl and C2H8N2 were used as nitrogen sources. The scanning electron microscopy, transmission electron microscopy and Raman spectroscopy were used to characterize the CNx nanotubes. It is found that not only the degrees of purity and ordering, but also the morphology of the CNx nanotubes are quite different when different nitrogen sources are used. The CNx nanotubes fabricated by pyrolyzing C2H8N2/C10H10Fe have "bamboo-like" structure and lower crystallinity, and grow horizontally in good order on silicon substrates. Low field emission measurement gives a turn-on field of 1.0 V/mu m and 860 mu A/cm(2) current density at 2.89 V/mu m.