Electrochemical assembled p-type Bi/sub 2/Te/sub 3/ nanowire arrays
Bi/sub 2/Te/sub 3/ nanowires have been assembled into the nanopores of alumina films by electrodeposition in the solution containing Bi/sup 3+/ and HTeO/sub 2//sup +/ with porous alumina template as cathode. The results show that p-type Bi/sub 2/Te/sub 3/ nanowires can be easily electrochemical organized into the nanopores of the template by controlling the deposition potential. The filling ratio of the nanowires in the nanopores of alumina template highly correlates with the structural uniformity of alumina template, the ionic concentration of Bi/sup 3+/ and HTeO/sub 2//sup +/ in the solution and the depositing rate of the nanowires. ESEM and TEM analyses indicate that the p-type Bi/sub 2/Te/sub 3/ nanowires were uniformly electrodeposited into the alumina template. The performance measurement verified that the Seebeck coefficient of p-type Bi/sub 2/Te/sub 3/ nanowire arrays fabricated in our lab was 270 /spl mu/V/K at 306 K, which is a little larger than that of bulk Bi/sub 2/Te/sub 3/ thermoelectric materials.