Growth of aligned SWNT arrays from water-soluble molecular clusters for nanotube device fabrication

A simple method to fabricate parallel and/or crossed networks of ultra-long single-walled carbon nanotube (SWNT) arrays based on carbon monoxide-chemical vapor deposition (CO-CVD) by a “fast-heating” growth process is reported. The catalysts which are water-soluble inorganic molecular clusters containing Fe and Mo atoms can be easily “drawn” on the substrate by an ink pen using the cluster solution as “ink” or transferred by micro-contact printing (µCP) using poly (dimethylsiloxane)(PDMS) elastomer stamp onto substrate. The as-grown SWNTs are millimetres in length with diameters ranging from 0.7 to 2.0 nm and with controllable location and direction. Multi-dimensional crossed-networks of SWNTs can be easily fabricated by multi-step growth processes. Patterning catalysts using water-soluble clusters can be compatible with ink-jet printing techniques for generating large-area well-oriented and precisely-located SWNTs. We have also demonstrated that the ease of patterning and growing aligned nanotube arrays provides a reliable way to fabricate nanotube electronic devices.