Thermoelectric Properties of Antiperovskite X<sub>3</sub>SiO (X = Sr and Ba)

Thermoelectric materials are useful for various application in daily life. Their application such as sensors, generators and electronic components, making thermoelectric materials widely studied. Antiperovskite compounds that can have semiconducting behaviour is probable candidate for thermoelectric materials. In this article, thermoelectric properties of anti-perovskite X 3 SiO (X = Sr and Ba) were investigated using density functional theory (DFT) method and Boltzmann Transport Equations (BTE). Electronic properties such as band structure, partial density of states were computed using the generalized gradient approximation with Perdew-Burke-Ernzerhof (GGA-PBE) functional in CASTEP code. The thermoelectric properties such as Seebeck coefficient, electrical conductivity, and power factor are calculated using BoltzTraP code that utilised BTE. The calculated band structures of Ba 3 SiO and Sr 3 SiO show that these compounds having semiconductor behaviour with direct band gap of 0.44 and 0.43 eV respectively at Γ-Γ k-point. It was found that Ba 3 SiO is a better candidate for thermoelectric materials due to its higher Seebeck coefficient (-4.90 10 -4 V/K) at room temperature compared to calculated Seebeck coefficient (-5.84 10 -4 V/K) of Sr 3 SiO. The power factor value of Ba 3 SiO which is 2.96 x 10 -4 W/mK 2 is also higher compared to power factor of Sr 3 SiO at 7.12 x 10 -7 W/mK 2 at room temperature.