n-type thermoelectric material Mg2Sn0.75Ge0.25 for high power generation.
Thermoelectric power generation is one of the most promising techniques to use the huge amount of waste heat and solar energy. Traditionally, high thermoelectric figure-of-merit, ZT, has been the only parameter pursued for high conversion efficiency. Here, we emphasize that a high power factor (PF) is equivalently important for high power generation, in addition to high efficiency. A new n-type Mg2Sn-based material, Mg2Sn0.75Ge0.25, is a good example to meet the dual requirements in efficiency and output power. It was found that Mg2Sn0.75Ge0.25 has an average ZT of 0.9 and PF of 52 μW⋅cm(-1)⋅K(-2) over the temperature range of 25-450 °C, a peak ZT of 1.4 at 450 °C, and peak PF of 55 μW⋅cm(-1)⋅K(-2) at 350 °C. By using the energy balance of one-dimensional heat flow equation, leg efficiency and output power were calculated with Th = 400 °C and Tc = 50 °C to be of 10.5% and 6.6 W⋅cm(-2) under a temperature gradient of 150 °C⋅mm(-1), respectively.
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002;
Weishu
W
Liu
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002;
Hee Seok
HS
Kim
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002;
Shuo
S
Chen
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002;
Qing
Q
Jie
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002;
Bing
B
Lv
Department of Physics, Boston College, Chestnut Hill, MA 02467; and.
Mengliang
M
Yao
Department of Physics, Boston College, Chestnut Hill, MA 02467; and.
Zhensong
Z
Ren
Department of Physics, Boston College, Chestnut Hill, MA 02467; and.
Cyril P
CP
Opeil
Department of Physics, Boston College, Chestnut Hill, MA 02467; and.
Stephen
S
Wilson
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002; Lawrence Berkeley National Laboratory, Berkeley, CA 94720 cwchu@uh.edu zren@uh.edu.
Ching-Wu
CW
Chu
Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002; cwchu@uh.edu zren@uh.edu.
Zhifeng
Z
Ren
magnesium; output power; power factor; thermoelectrics; tin