Field emission from carbon nanotubes deposited on platinum and nickel/nickel oxide multilayers

Abstract

Although carbon nanotubes have been shown to be excellent field emitters, very little is known about the emission mechanism. This work strives to gain insight on field enhancement in films of single-walled carbon nanotubes by studying the internal field emission between the back contact metal and the nanotubes, and the external field emission between the nanotubes and vacuum. Test devices of different work functions were fabricated from platinum and from nickel / nickel oxide. Nickel oxide was deposited by e-beam evaporation or grown by thermal oxidation and characterized by Auger electron spectroscopy, x-ray diffraction and ellipsometry. Carbon nanotubes were deposited onto these test structures and current-voltage measurements were taken. Fowler-Nordheim plots were constructed from this data and analyzed. It was determined that external field emission was most likely to be responsible for electron emission.