Growth of carbon nanotubes on cobalt catalyst film using electron cyclotron resonance chemical vapour deposition without thermal heating

This paper demonstrates that carbon nanotubes (CNTs) can be synthesized on a cobalt coated silicon substrate using electron cyclotron chemical vapour deposition and without intentionally heating the substrate. With the mixed gases of C(3)H(8)/N(2), CNTs with a multi-walled structure and a diameter up to 70?nm have been observed. Results show that the diameter of the CNTs increases with the thickness of the cobalt catalyst film and the amount of nitrogen incorporated in the CNT films considerably influences the structures of the CNTs. Vertically aligned CNTs can be fabricated with a microwave power as low as 300?W and the flow rate ratio of C(3)H(8)/N(2) = 20/20?sccm. The CNTs exhibit a turn-on field of 0.2?V?μm(-1) determined at the emission current density of 10?μA?cm(-2).