High thermopower and ultra low thermal conductivity in Cd-based Zintl phase compounds

Pandey, Tribhuwan and Singh, Abhishek K (2015) High thermopower and ultra low thermal conductivity in Cd-based Zintl phase compounds. In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 17 (26). pp. 16917-16926.

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Abstract

By combining first principles density functional theory and electronic as well as lattice Boltzmann transport calculations, we unravel the excellent thermoelectric properties of Zintl phase compounds ACd(2)Sb(2) (where, A = Ca, Ba, Sr). The calculated electronic structures of these compounds show charge carrier pockets and heavy light bands near the band edge, which lead to a large power factor. Furthermore, we report large Gruneisen parameters and low phonon group velocity indicating essential strong anharmonicity in these compounds, which resulted in low lattice thermal conductivity. The combination of low thermal conductivity and the excellent transport properties give a high ZT value of similar to 1.4-1.9 in CaCd2Sb2 and BaCd2Sb2 at moderate p and n-type doping. Our results indicate that well optimized Cd-based Zintl phase compounds have the potential to match the performance of conventional thermoelectric materials.

Item Type:	Journal Article
Publication:	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Publisher:	ROYAL SOC CHEMISTRY
Additional Information:	Copy right for this article belongs to the ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	31 Jul 2015 13:58
Last Modified:	31 Jul 2015 13:58
URI:	http://eprints.iisc.ac.in/id/eprint/51970

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