Aligned nitrogen-containing carbon nanofibers consisting of polymerized “nanobells” have been grown on a large scale using microwave plasma-assisted chemical-vapor deposition with a mixture of methane and nitrogen. A greater part of the fiber surface consists of open ends of the graphitic sheets. A side-emission mechanism is proposed. A low-threshold field of 1.0 V/μm and a high-emission current density of 200 mA/cm2 for an applied field of 5–6 V/μm were achieved, implying that the materials have a high potential for future application as electron field emitters, especially in flat-panel displays.

The CNx/carbon nanotube junctions were successfully synthesized by microwave plasma-assisted chemical vapor deposition method from the mixture of N2/CH4 and H2/CH4 gases in a continuous growth process. High resolution transmission electron microscopy revealed that these junctions were of heterostructure between CNx nanotubes with polymerized nanobells and cylindrical carbon nanotubes. The growth process is quite simple and can be easily scaled up. The intimate correlation between the electronic structure and the chemical composition at the both sides of the junction indicate some interesting properties and offers potential applications for future nanodevices.

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