title: High-thermoelectric performance of nanostructured bismuth antimony telluride bulk alloys.
abstract: The dimensionless thermoelectric figure of merit (ZT) in bismuth antimony telluride (BiSbTe) bulk alloys has remained around 1 for more than 50 years. We show that a peak ZT of 1.4 at 100 degrees C can be achieved in a p-type nanocrystalline BiSbTe bulk alloy. These nanocrystalline bulk materials were made by hot pressing nanopowders that were ball-milled from crystalline ingots under inert conditions. Electrical transport measurements, coupled with microstructure studies and modeling, show that the ZT improvement is the result of low thermal conductivity caused by the increased phonon scattering by grain boundaries and defects. More importantly, ZT is about 1.2 at room temperature and 0.8 at 250 degrees C, which makes these materials useful for cooling and power generation. Cooling devices that use these materials have produced high-temperature differences of 86 degrees , 106 degrees , and 119 degrees C with hot-side temperatures set at 50 degrees, 100 degrees, and 150 degrees C, respectively. This discovery sets the stage for use of a new nanocomposite approach in developing high-performance low-cost bulk thermoelectric materials.
authors: Department of Physics, Boston College, Chestnut Hill, MA 02467, USA.
authors: Bed
authors: B
authors: Poudel
authors: Qing
authors: Q
authors: Hao
authors: Yi
authors: Y
authors: Ma
authors: Yucheng
authors: Y
authors: Lan
authors: Austin
authors: A
authors: Minnich
authors: Bo
authors: B
authors: Yu
authors: Xiao
authors: X
authors: Yan
authors: Dezhi
authors: D
authors: Wang
authors: Andrew
authors: A
authors: Muto
authors: Daryoosh
authors: D
authors: Vashaee
authors: Xiaoyuan
authors: X
authors: Chen
authors: Junming
authors: J
authors: Liu
authors: Mildred S
authors: MS
authors: Dresselhaus
authors: Gang
authors: G
authors: Chen
authors: Zhifeng
authors: Z
authors: Ren