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.
Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Giri
G
Joshi
Hohyun
H
Lee
Yucheng
Y
Lan
Xiaowei
X
Wang
Gaohua
G
Zhu
Dezhi
D
Wang
Ryan W
RW
Gould
Diana C
DC
Cuff
Ming Y
MY
Tang
Mildred S
MS
Dresselhaus
Gang
G
Chen
Zhifeng
Z
Ren