Growth of periodic carbon nanotube structures using nanosphere lithography

We have developed a low-cost method to grow carbon nanotubes in a periodic structure by using nanosphere lithography and plasma enhanced chemical vapor deposition technique. In this approach, the polystyrene monolayer colloidal crystal was used as a mask for deposition of catalyst layers by solution dipping method. Periodic bowl-like Fe2O3 array films obtained after the removal of polystyrene nanospheres were employed for the growth of carbon nanotubes. Through the regulation of the diameter of polystyrene nanospheres and plasma treatment conditions, we have grown carbon nanotube bundles into a honeycomb structure and a unique hexagonal lattice structure. The proposed method greatly reduces the fabrication cost and can tune the periodic structure of carbon nanotubes quite flexibly.