Unprecedented re-growth of carbon nanotubes on in situ re-activated catalyst

A simple-stepped growth process for the synthesis of carbon nanotubes that exhibit excellent field emission properties is reported. In the process, the growth was interrupted, and during the interruption the catalyst was re-activated in situ, resulting in enhanced growth of the CNTs after the interruption. A film of CNTs re-grows on top of an existing CNT film at much higher rates, which can be up to 669% higher. The tubular structure continues during the re-growth. The structural continuity creates an opportunity for the fabrication of junction CNTs for nano-electronic applications. The resulting CNTs also have excellent field emission properties, exhibiting an extremely low turn-on field of 0.10 V νm^-1.