Enhanced thermoelectric figure-of-merit in nanostructured p-type silicon germanium bulk alloys.
A dimensionless thermoelectric figure-of-merit (ZT) of 0.95 in p-type nanostructured bulk silicon germanium (SiGe) alloys is achieved, which is about 90% higher than what is currently used in space flight missions, and 50% higher than the reported record in p-type SiGe alloys. These nanostructured bulk materials were made by using a direct current-induced hot press of mechanically alloyed nanopowders that were initially synthesized by ball milling of commercial grade Si and Ge chunks with boron powder. The enhancement of ZT is due to a large reduction of thermal conductivity caused by the increased phonon scattering at the grain boundaries of the nanostructures combined with an increased power factor at high temperatures.
Joshi
Giri
G
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Lee
Hohyun
H
Lan
Yucheng
Y
Wang
Xiaowei
X
Zhu
Gaohua
G
Wang
Dezhi
D
Gould
Ryan W
RW
Cuff
Diana C
DC
Tang
Ming Y
MY
Dresselhaus
Mildred S
MS
Chen
Gang
G
Ren
Zhifeng
Z