Sr₂Sb₂O₇: a novel earth abundant oxide thermoelectric

Thermoelectric devices are increasingly proving to be a viable energy recycling method, with oxide thermoelectrics providing an earth abundant and non-toxic alternative to the materials traditionally used in the field. This study conducts a detailed investigation into the thermoelectric properties of the ternary wide band semiconductor Sr₂Sb₂O₇, which has previously been synthesised under high temperature conditions and shown to be thermally stable. Lattice dynamics calculations predict lattice thermal conductivities below 1 W m⁻¹ K⁻¹ at temperatures above 1125 K. The Seebeck coefficient, electrical conductivity and electronic component to the thermal conductivity were calculated via the explicit calculation of the polar optical phonon scattering, acoustic deformation potential scattering and ionised impurity scattering rates within the AMSET code. The obtained results were combined to obtain a maximum ZT of 0.536 at 1400 K, which when nanostructured to 10 nm was increased to 0.71, showing its predicted potential to perform as a high-performance n-type oxide thermoelectric.