A novel density control of carbon nanotubes by partial oxidation of catalyst metal and its field emission enhancement

A novel density control of carbon nanotubes is fabricated using partial oxidation of catalyst metal prior to the CNTs growth. The results show that CNTs are aligned, closely spaced, and divided into two groups with some long nanotubes protruding among short ones. Field emission improvement is achieved due to those long nanotubes are subjected less field screening effect from the surrounding nanotubes. The obtained results show that a low turn-on field (1.9 V/μm) and an ultra high field emission current density (160mA/cm2 at 6 V/μm) can be achieved through this novel morphology of CNTs.