Deposition of Nanotubes and Nanotube Composites using Matrix-Assisted Pulsed Laser Evaporation

Using the Matrix-Assisted Pulsed Laser Evaporation (MAPLE) process developed at the Naval Research Laboratory, carbon nanotubes and carbon nanotube composite thin films have been successfully fabricated. This process involves dissolving or suspending the film material in a volatile solvent, freezing the mixture to create a solid target, and using a low fluence pulsed laser to evaporate the target for deposition inside a vacuum system. The collective action of the evaporating solvent desorbs the polymer/nanotube composite from the target. The volatile solvent is then pumped away leaving the film material on the substrate. By using this technique singlewall-nanotubes (SWN) have been transferred from the target to the substrate. The SWN sustain no observable damage during the deposition process. Using SWN in combination with polymers as the target material, SWN/polystyrene and SWN/polyethylene glycol composite films were made. These films can be deposited on a variety of substrates, e.g., Si, glass, plastic, and metal, using the same target and deposition conditions. SEM micrographs show that the SWN were uniformly distributed in the film. Using a simple contact mask, SWN composite films 20 um diameter patterns can be produced.