Influence of germanium nano-inclusions on the thermoelectric power factor of bulk bismuth telluride alloy
Abstract
Nanocomposite thermoelectric compound of bismuth telluride (Bi2Te3) 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 Bi2Te3 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 27, 2014
- Source ID
- 10.1063/1.4873239
Entities
People
- Armin Tahmasbi Rad
- Daryoosh Vashaee
- Jerzy S. Krasiński
- Lobat Tayebi
- Nikhil Satyala
- Payam Norouzzadeh
- Zahra Zamanipour
Organizations
- Air Force Office of Scientific Research
- Oklahoma State University–Stillwater