Aligned Carbon Nanotube Films: Production and Optical and Electronic Properties

TLDR

Carbon nanotube material can now be produced in macroscopic quantities, but its disordered structure limits investigation of its properties and applications. The study develops a method to produce thin films of aligned carbon nanotubes. Thin films of aligned carbon nanotubes are produced by a newly developed method. Scanning electron microscopy confirms that the films can be aligned parallel or perpendicular to the surface; parallel alignment yields birefringence due to anisotropic dielectric functions, and electrical resistivity is lower along the tubes than across them, reflecting anisotropic electronic transport.

Abstract

Carbon nanotube material can now be produced in macroscopic quantities. However, the raw material has a disordered structure, which restricts investigations of both the properties and applications of the nanotubes. A method has been developed to produce thin films of aligned carbon nanotubes. The tubes can be aligned either parallel or perpendicular to the surface, as verified by scanning electron microscopy. The parallel aligned surfaces are birefringent, reflecting differences in the dielectric function along and normal to the tubes. The electrical resistivities are anisotropic as well, being smaller along the tubes than perpendicular to them, because of corresponding differences in the electronic transport properties.