Controlled chemical routes to nanotube architectures, physics, and devices

This article presents our recent work in the controlled synthesis of multiw alled (MWNT) and single-walled nanotubes (SWNT) with ordered architectures. The general synthesis approach involves chemical vapor deposition using ra tionally designed catalyst and substrates. The results include self-oriente d MWNTs, individual SWNTs grown from controlled surface sites, and structur es of suspended SWNTs along well-defined directions. The chemically derived nanotube architectures have opened up new possibilities in fundamental cha racterization and potential applications of nanotube materials. Systematic electron transport measurements are carried out to elucidate the electrical properties of various classes of SWNTs and to explore the physics in one-d imensional systems. High-performance electrical devices based on individual SWNTs are enabled by combining synthesis and microfabrication approaches.