Uniform arrays of carbon nanotubes applied in the field emission devices

Carbon nanotubes (CNTs) were grown into anodic aluminum oxide (AAO) channels by chemical vapor deposition (CVD) using C2H2/N-2 mixtures as feeding gas, which can be used as field emitters. The bottom surface of AAO template was etched slightly and the tips of CNTs were explored as the field emission arrays which were uniform and vertical. Field emission characterization showed a low turn-on field about 3.25 V/mu m and high emission current about 30 mA/cm(2) with the electric field about 4 V/mu m. These superior field emission characteristics could be attributed to low density of vertical CNTs and higher conductivity of the substrate.