Patterned growth and contact transfer of well-aligned carbon nanotube films

The preparation of aligned and/or micropatterned carbon nanotubes is important to applications ranging from nanocomposites to field-emitting displays. By pyrolysis of iron (II) phthalocyanine under Ar/H-2 at 800-1100 degrees C, we have synthesized large arrays of vertically aligned carbon nanotubes on various substrates, including quartz glass plates, from which substrate-free films were obtained simply by immersing the nanotube-deposited quartz plates into an aqueous hydrofluoric acid solution. Micropatterns of the aligned nanotubes suitable for device fabrication were generated either by patterned growth of the nanotubes on a partially masked/prepatterned surface or through a contact printing process involving region-specific transfer of the substrate-free nanotube films to other substrates (e.g., polymer films), which otherwise may not be suitable for nanotube growth at high temperatures.