Abstract
Doping with foreign atom has been shown to be an effective way to enhance the dimensionless figure of merit ZT of Bi2Te3-based thermoelectric raw materials. Herein, we report that doping with Nb is effective in enhancing the Seebeck coefficient of n-type Cu0.008Bi2Te2.7Se0.3 polycrystalline bulks. Considering compensation of the Seebeck coefficient due to decrease of the electrical conductivity in Nb-doped compositions, the absolute value of Seebeck coefficient rather increased benefiting from an enhancement of the density of states (DOS) effective mass m* from 1.09m0 (Cu0.008Bi2Te2.7Se0.3) to 1.21m0 − 1.27m0 (Cu0.008Bi2−xNbxTe2.7Se0.3) due to a DOS engineering effect. The values of ZT were 0.84 at 300 K and 0.86 at 320 K for Cu0.008Bi1.99Nb0.01Te2.7Se0.3. This compositional tuning approach highlights the possibility of further enhancement of ZT for n-type Bi2Te3-based compounds by using a combination of nanostructuring technologies to reduce the thermal conductivity.
Original language | English |
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Pages (from-to) | 7-11 |
Number of pages | 5 |
Journal | Journal of the Korean Physical Society |
Volume | 68 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2016 Jan 1 |
Bibliographical note
Funding Information:This work was supported by a Human Resources Development program (No. 20124010203270) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government’s Ministry of Trade, Industry and Energy. J.H. Lee was supported by a Research Grant from Kwangwoon University in 2014.
Publisher Copyright:
© 2016, The Korean Physical Society.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)