Published online by Cambridge University Press: 01 February 2011
Bismuth telluride (Bi2Te3) and its alloys have long been held as the best bulk commercial thermoelectric (TE) materials. In recent years, significant enhancement of the TE figure of merit (ZT) of these traditional TE materials has been predicted through reduction of dimensions (i.e., nanostructures and nanoengineering). We are particularly interested investigating electrolyte composition variations to control the composition of nanowires to enable large ZT enhancement. We report here the constant current electrochemical deposition of BixTey nanowires of diameters of 35, 55, 73 and 200 nm and lengths up to 50 microns. We are able to obtain controlled, uniform growth of high quality n-type bismuth telluride nanowires. A design of experimental matrix investigating the effects of current density and solution pH values on the overall growth rate and nanowire crystalline quality has been performed. The effects of growth conditions on materials and structural characteristics of BixTey nanowires have been studied by SEM, High Resolution TEM, EDX, concentric beam electron diffraction patterns, and ICP. The TE properties of individual BixTey nanowires are currently being evaluated using micro/nano fabricated devices and UHV Scanning Thermoelectric Microscopy.