ABSTRACT
Thermoelectric (TE) materials can directly convert heat into electricity through the Seebeck effect and thereby have potential application in waste heat recovery in transportation, industrial, commercial, and residential processes. The efciency of conversion of heat into electricity for a TE device is determined by the gure of merit ZT = (S2σ/k)T, where S is the Seebeck coefcient, σ is the electrical conductivity, and k is the total thermal conductivity. A good TE material should possess high Seebeck coefcient, high electrical conductivity, and low thermal conductivity. Since the electronic part of thermal conductivity is governed by the Wiedemann-Franz law and thus is coupled to the electrical conductivity, minimizing the lattice thermal conductivity is crucial to improve the gure of merit of TE materials. Although progress has been made in the design and synthesis of new TE materials during the last decade by reducing lattice thermal conductivity through solid solution formation or nanostructuring, thereby increasing the value of gure of merit to over two (almost 20% efciency at typical operating temperatures), TE power generation is still far from large-scale application
CONTENTS
16.1 Introduction ........................................................................................................................ 473 16.2 Intrinsic Low Thermal Conductivity and Crystal Structure of Tetrahedrites ............ 474
16.2.1 Large Primitive Unit Cell Volume ....................................................................... 475 16.2.2 “Rattling” Atoms ................................................................................................... 475 16.2.3 Strong Anharmonicity .......................................................................................... 475
16.3 Electronic Structure and Electrical Transport Properties of Tetrahedrites ............... 479 16.4 Codoping ............................................................................................................................. 482 16.5 Direct Use of Natural Mineral Tetrahedrites and Other Rapid Synthesis
Methods ............................................................................................................................... 482 16.6 Mechanical Properties and Structure Stability of Tetrahedrites ................................483 16.7 Conclusions and Future Work .........................................................................................485 Acknowledgments ......................................................................................................................485 References .....................................................................................................................................486
