Potential thermoelectric material Sr2TiMoO6 from ab initio calculations

Fan Qiang,Yang Jian Hui

doi:10.1088/1757-899x/382/2/022024

Abstract

The thermoelectric properties of double perovskite Sr2TiMoO6 have been systematically proposed by using semi-classic Boltzmann transport theory based on the electronic structure from first principle. The transport properties for the spin-up and spin-down electrons of double perovskite Sr2TiMoO6 compounds have been demonstrated. The metallic spin-up channel results in considerable electronic conductivity. For the big band gap, there are small electronic conductivity and zero Seebeck coefficients at low temperatures for semiconducting spin-down channel. The optimal ZT values at 900 K reach to 1.28 and 1.35 for p-type doping and n-type doping, respectively. Considering the ZT value is sizable, double perovskite Sr2TiMoO6 is a potential candidate in thermoelectric device.

Highlights

Researchers pay close attention to thermoelectric materials due to which can convert directly the waste heat into useful electrical energy [1, 2]
The conversion efficiency between heat and electricity of thermoelectric material is defined by a dimensionless figure of merit (ZT), which is identified as: ZT = S2σT⁄(ke + kl), where S, σ and T are Seebeck coefficient, electrical conductivity and temperature respectively. ke and kl are thermal conductivities contributed from electron and lattice respectively
We address the thermoelectric property of double perovskite Sr2TiMoO6 from first principles in order to provide reference data for further experimental and theoretical research

Summary

Introduction

Researchers pay close attention to thermoelectric materials due to which can convert directly the waste heat into useful electrical energy [1, 2]. The conversion efficiency between heat and electricity of thermoelectric material is defined by a dimensionless figure of merit (ZT), which is identified as: ZT = S2σT⁄(ke + kl), where S, σ and T are Seebeck coefficient, electrical conductivity and temperature respectively. Ke and kl are thermal conductivities contributed from electron and lattice respectively. S2σ is named power factor (PF) of thermoelectric material. Improving PF and decreasing thermal conductivity are typical ways to achieve high thermoelectric performance with large ZT value. It is technically difficult to optimize the ZT value for the coupling of S, σ through carrier concentration. The discovery of new materials with high thermoelectric performance has been pursued by materials designers

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