In situ-grown carbon nanotube array with excellent field emission characteristics

Abstract

In situ catalytic thermal decomposition method was used for producing aligned multiwalled carbon nanotubes (MWNTs) in bulk quantities on stable and electrically conducting substrates. Very low turn-on electric fields of 0.75 V/μm and low threshold fields of ∼1.6 V/μm (for current density of 10 ${\mathrm{mA/cm}}^2)$ were obtained from the MWNT arrays grown on TiN substrate. Furthermore, large emission current densities of 1–3 ${\mathrm{A/cm}}^2$ were obtained at reasonably low fields of less than ∼8 V/μm. These enhanced emission properties are tentatively attributed to the oriented and high-density nature of the emitting carbon nanotube structure and the high-conductivity, stable nature of the TiN substrate onto which the nanotubes are attached.