Comparison of the field emissions between highly ordered carbon nanotubes with closed and open tips

Abstract

We have studied the field emission from the closed and open tips of highly ordered carbon nanotubes fabricated on porous anodic aluminum oxide templates by changing the tube height. Due to the field-screening effect provoked by the proximity of the neighboring tubes, the field emission from both kinds of the tips was critically affected by the tube height that protruded from the surface. The field emission optimizes when the tube height is similar to the intertube distance for both kinds of tips. The field emission from the closed tips is much more efficient than that from the open ones.