Zintl-phase compounds with SnSb₄ tetrahedral anions. Electronic structure and thermoelectric properties

Journal Article · Mon Feb 22 04:00:00 EST 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.81.075117· OSTI ID:1064678

Zhang, Lijun ^[1]; Du, Mao-Hua ^[1]; Singh, David J. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

We report the investigation of Zintl-phase Na(K){sub 8}SnSb{sub 4} and related compounds that contain SnSb{sub 4} tetrahedral anions using first principles electronic structure, Boltzmann transport, and density functional phonon calculations. We find that these compounds are narrow-gap semiconductors and there is a combination of heavy and light bands at valence band edge, which may lead to a combination of high thermopower and reasonable conductivity. High values of the thermopower are found for p-type doping within the Boltzmann transport theory. Furthermore, these materials are expected to have low thermal conductivity due to their structures that consist of a network of weakly coupled SnSb{sub 4} clusters, which leads to low phonon frequencies. In particular, we find low-frequency optical phonons that should effectively scatter the heat-carrying acoustic phonons. These results are discussed in terms of the structure, which consists of anionic clusters. Based on the results, it is suggested that such compounds may represent a useful paradigm for finding new thermoelectric materials.

• Research Organization: Energy Frontier Research Centers (EFRC); Solid-State Solar-Thermal Energy Conversion Center (S3TEC)
• Sponsoring Organization: USDOE SC Office of Basic Energy Sciences (SC-22)
• DOE Contract Number: SC0001299; SC0001299
• OSTI ID: 1064678
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 07 Vol. 81; ISSN 1098-0121
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
charge transport
defects
materials and chemistry by design
mechanical behavior
optics
phonons
solar (photovoltaic)
solar (thermal)
solid state lighting
spin dynamics
synthesis (novel materials)
synthesis (scalable processing)
synthesis (self-assembly)
thermal conductivity
thermoelectric