Highly ordered two-dimensional carbon nanotube arrays

Highly ordered multiwalled carbon nanotube arrays have been fabricated by using porous anodic alumina templates prepared by a two-step anodization process. Nanotubes were very uniform in diameter. Two-dimensional tube arrays were highly ordered within domain boundaries, and their vertical alignment was nearly perfect. The density of nanotubes, 1.1×1010 tubes/cm2, was very high. Our fabrication technique enabled us to easily control the tube diameter, length, and density. There was no practical limitation to the size of the alumina template, so that very large panels of well-aligned carbon nanotubes could be made. Our results offer a potentially elegant technique for fabricating cold-cathode flat panel displays.