High thermoelectric figure of merit and improved mechanical properties in melt quenched PbTe-Ge and PbTe-Ge1-xSix eutectic and hypereutectic composites

被引：54

作者：

Sootsman, Joseph R. ^{[1
]}

He, Jiaqing ^{[2
]}

Dravid, Vinayak P. ^{[2
]}

Li, Chang-Peng ^{[3
]}

Uher, Ctirad ^{[3
]}

Kanatzidis, Mercouri G. ^{[1
,4
]}

机构：

[1] Northwestern Univ, Dept Chem, Evanston, IL 60208 USA

[2] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA

[3] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA

[4] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA

来源：

JOURNAL OF APPLIED PHYSICS | 2009年 / 105卷 / 08期

关键词：

brittleness; carrier density; composite materials; electrical conductivity; elemental semiconductors; eutectic structure; fracture toughness; germanium; Ge-Si alloys; IV-VI semiconductors; lead compounds; melt processing; thermal conductivity; thermoelectricity; THERMAL-CONDUCTIVITY; SOLID-SOLUTIONS; ALLOYS; NANOSTRUCTURES; AGPBMSBTE2+M; SYSTEM; POWER;

D O I：

10.1063/1.3093833

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We report the synthesis, microstructure, and transport properties of composite thermoelectric materials based on the eutectic phase relationship between PbTe and Ge. When quenched, these eutectic mixtures exhibit considerably stronger mechanical strength and reduced brittleness compared to PbTe itself, while at the same time they possess lower lattice thermal conductivity. Thermal conductivity measurements show values lower than expected based on the law of mixtures and multiphase composites. We find that the thermoelectric performance in these composites can be tuned through the use of hypereutectic compositions and alloying of Ge with Si. PbI2 was used as an n-type dopant, and precise control of the carrier concentration was achieved to optimize the electrical transport and thermoelectric properties. ZT values approaching 1.3 at 778 K have been obtained in samples of PbTe-Ge0.8Si0.2(5%), which represent an similar to 62% improvement over that of PbTe.

引用

页数：8