Fabrication and Characterization of Aligned Metallic Carbon Nanotube Thin Films

The one-dimensional nature of individualized single wall carbon nanotubes (SWCNTs) allows for them to exhibit highly anisotropic mechanical, optical, electrical, and thermal behaviors. However, producing macroscopic alignment of SWCNT ensembles has proven difficult, which has hindered scientific and industrial investigations into their anisotropic properties. Here, we explore the optical and electronic behavior of aligned, metallic SWCNT thin films, produced using a slow vacuum filtration method. We measure the degree of nanotube alignment using a variety of polarized optical measurements, including optical imaging, Raman, terahertz, and absorption spectroscopy. From these techniques, we observe a nematic ordering parameter of 0.3, which is confirmed via polarized Raman spectroscopy. The high metallicity of these films, and the strong, anisotropic absorption of the metallic nanotubes, suggests their potential use as a broadband linear polarizer.