Growth and characterization of Bi/sub 2/Te/sub 3/ nanostructures

Bulk Bi/sub 2/Te/sub 3/ is one of the best known thermoelectric materials with a ZT /spl sim/1 at room temperature. Theoretical studies have suggested that low-dimensional materials may exhibit ZT values that exceed 1. In this study, we used the pulsed laser deposition method to prepare Bi/sub 2/Te/sub 3/ nanostructures by ablating a rotating Bi/sub 2/Te/sub 3/ target in an inert atmosphere. Silicon or quartz substrates are pretreated with poly-1-lysine to form an adhesion layer for 10, 20, and 30 nm colloidal Au particles which serve as catalyst seed particles for the growth of the nanostructures. Alternatively, we have also prepared Bi/sub 2/Te/sub 3/ nanostructures by subliming Bi/sub 2/Te/sub 3/ powder in the presence of gold coated substrates. Results from electron microscopy and vibrational spectroscopic studies are presented.