Anisotropic Electrical Properties from Vapor-Solid-Solid Grown Bi2Se3 Nanoribbons and Nanowires

High-quality Bi2Se3 nanoribbons and nanowires were synthesized by a Au-catalyzed chemical vapor deposition method. Detailed structural and chemical characterizations using scanning and transmission electron microscopy show that the growth of both Bi2Se3 nanoribbons and nanowires is governed by the vapor-solid-solid growth mechanism, and the nanoribbons grow along < 11 (2) over bar0 > and nanowires grow along < 0001 > directions. Detailed in situ scanning tunneling microscope-transmission electron microscopy electrical measurements show that the nanoribbons are much more conductive than the nanowires with a conductivity anisotropy ratio of similar to 2.5 x 10(2) at room temperature.