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 (lCP) 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 preciselylocated SWNTs. We have also demonstrated that the ease of patterning and growing aligned nanotube arrays provides a reliable way to fabricate nanotube electronic devices.