11-02/03 :: February / March 2011
nanotimes News in Brief
Materials // Bi2
Te3 T -based TE Nanocomposites
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hermoelectric (TE) materials can be used to directly convert between heat and electricity
through the Seebeck effect and Peltier effect. They usually act as solid state refrigerators and heat pumps without moving parts and environmentally harmful fluids.
Bismuth telluride (Bi2Te3 ) based alloys are one of the
most excellent TE materials at room temperature, used commercially for refrigeration and temperature control in fields such as beverage coolers and laser diode coolers. The TE figure of merit (ZT) of com- mercial Bi2
Te3 -based alloys is only about 1.0. To in-
crease the efficiency for widely practical applications, materials with higher ZT are desired to be explored.
Recently, the Division of Functional Materials and Nanodevices in Ningbo Institute of Materials Tech- nology &. Engineering (NIMTE), China, has made a series of progress in nanostructured Bi2
Te3 composites.
By embedding ZnAlO nanopowder with high elec- trical conductivity into matrix, p-type Bi2
Te3 -based
TE nanocomposite was prepared using zone melting method. A peak ZT of 1.33 at 370 K was achieved, mainly due to the remarkably increased electrical conductivity and the simultaneously decreased lattice thermal conductivity caused by the introduction
Ting Zhang, Qiushi Zhang, Jun Jiang, Zhen Xiong, Jianmin Chen, Yulong Zhang, Wei Li, and Gaojie Xu: Enhanced thermoelectric performance in p-type BiSbTe bulk alloy with nanoinclusion of ZnAlO, In: Applied Physics Letters, Vol. 98(2011), Issue 2, January 10, 2011, Article 022104 (3 pages), DOI:10.1063/1.3541654 : http://dx.doi.org/10.1063/1.3541654
-based TE
of ZnAlO nanopowder. Through the post sintering process, ZT value of this Bi2
Te3 could reach up to 1.4.
Temperature dependence of ZT for Bi2Te3-based composites, © NIMTE
-based nanocomposite