Airan Li1, Chenguang Fu2, Xinbing Zhao1, Tiejun Zhu1. 1. State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, 310027 Hangzhou, China. 2. Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
Abstract
Since the first successful implementation of n-type doping, low-cost Mg3Sb2-x Bi x alloys have been rapidly developed as excellent thermoelectric materials in recent years. An average figure of merit zT above unity over the temperature range 300-700 K makes this new system become a promising alternative to the commercially used n-type Bi2Te3-x Se x alloys for either refrigeration or low-grade heat power generation near room temperature. In this review, with the structure-property-application relationship as the mainline, we first discuss how the crystallographic, electronic, and phononic structures lay the foundation of the high thermoelectric performance. Then, optimization strategies, including the physical aspects of band engineering with Sb/Bi alloying and carrier scattering mechanism with grain boundary modification and the chemical aspects of Mg defects and aliovalent doping, are extensively reviewed. Mainstream directions targeting the improvement of zT near room temperature are outlined. Finally, device applications and related engineering issues are discussed. We hope this review could help to promote the understanding and future developments of low-cost Mg3Sb2-x Bi x alloys for practical thermoelectric applications.
Since the first successful impn>lementation of n-typn>e dopn>ing, low-cost n>an class="Chemical">Mg3Sb2-x Bi x alloys have been rapidly developed as excellent thermoelectric materials in recent years. An average figure of merit zT above unity over the temperature range 300-700 K makes this new system become a promising alternative to the commercially used n-type Bi2Te3-x Se x alloys for either refrigeration or low-grade heat power generation near room temperature. In this review, with the structure-property-application relationship as the mainline, we first discuss how the crystallographic, electronic, and phononic structures lay the foundation of the high thermoelectric performance. Then, optimization strategies, including the physical aspects of band engineering with Sb/Bi alloying and carrier scattering mechanism with grain boundary modification and the chemical aspects of Mg defects and aliovalent doping, are extensively reviewed. Mainstream directions targeting the improvement of zT near room temperature are outlined. Finally, device applications and related engineering issues are discussed. We hope this review could help to promote the understanding and future developments of low-cost Mg3Sb2-x Bi x alloys for practical thermoelectric applications.
Authors: Riley Hanus; Matthias T Agne; Alexander J E Rettie; Zhiwei Chen; Gangjian Tan; Duck Young Chung; Mercouri G Kanatzidis; Yanzhong Pei; Peter W Voorhees; G Jeffrey Snyder Journal: Adv Mater Date: 2019-04-10 Impact factor: 30.849