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Title: Influence of germanium nano-inclusions on the thermoelectric power factor of bulk bismuth telluride alloy

Nanocomposite thermoelectric compound of bismuth telluride (Bi{sub 2}Te{sub 3}) with 5 at. % germanium nano-inclusions was prepared via mechanically alloying and sintering techniques. The influence of Ge nano-inclusions and long duration annealing on the thermoelectric properties of nanostructured Bi{sub 2}Te{sub 3} were investigated. It was found that annealing has significant effect on the carrier concentration, Seebeck coefficient, and the power factor of the thermoelectric compound. The systematic heat treatment also reduced the density of donor type defects thereby decreasing the electron concentration. While the as-pressed nanocomposite materials showed n-type properties, it was observed that with the increase of annealing time, the nanocomposite gradually transformed to an abundantly hole-dominated (p-type) sample. The long duration annealing (∼500 h) resulted in a significantly enhanced electrical conductivity pertaining to the augmentation in the density and the structural properties of the sample. Therefore, a simultaneous enhancement in both electrical and Seebeck coefficient characteristics resulted in a remarkable increase in the thermoelectric power factor.
Authors:
; ; ; ;  [1] ;  [2] ;  [3]
  1. School of Electrical and Computer Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, Oklahoma 74106 (United States)
  2. School of Material Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, Oklahoma 74106 (United States)
  3. School of Chemical Engineering, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
Publication Date:
OSTI Identifier:
22304353
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 20; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; BISMUTH TELLURIDES; CARRIERS; DEFECTS; DENSITY; ELECTRIC CONDUCTIVITY; GERMANIUM ADDITIONS; INCLUSIONS; NANOSTRUCTURES; SINTERING; THERMOELECTRIC PROPERTIES