Self-organized carbon nanotips

We have developed a carbon nanostructure, which is comprised of high-density carbon nanotips on a graphite layer. These carbon nanotips, with tip diameters of $\text{∼10\hspace{0.05em}}\mathrm{nm},$ are grown by high-density plasma chemical vapor deposition onto Ni-coated Si using an inductively coupled plasma. The Ni on Si changes into ${\mathrm{NiSi}}_{\mathrm{2}}$ by substrate heating. First, a carbon buffer layer and then a graphene sheet are formed on the ${\mathrm{NiSi}}_{\mathrm{2}}.$ Then, the carbon nanotips are grown by a ${\mathrm{C}}_{\mathrm{2}}{\mathrm{H}}_{\mathrm{2}}{\mathrm{/H}}_{\mathrm{2}}$ plasma on the graphene sheet. The carbon nanotips show good adhesion to the substrate and are almost aligned, with an average length of 110 nm. They exhibit a turn-on field of 0.1 V/μm, a field amplification factor of $\text{∼13\hspace{0.05em}000,}$ a current density of $\text{2\hspace{0.05em}}{\mathrm{mA/cm}}^{\mathrm{2}}$ at a field of 2 V/μm, and uniform electron emission.