Controlled chemical routes to nanotube architectures, physics, and devices

This article presents our recent work in the controlled synthesis of multiwalled (MWNT) and single-walled nanotubes (SWNT) with ordered architectures. The general synthesis approach involves chemical vapor deposition using rationally designed catalyst and substrates. The results include self-oriented MWNTs, individual SWNTs grown from controlled surface sites, and structures of suspended SWNTs along well-defined directions. The chemically derived nanotube architectures have opened up new possibilities in fundamental characterization 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-dimensional systems. High-performance electrical devices based on individual SWNTs are enabled by combining synthesis and microfabrication approaches.