Electric Structure and Thermoelectric Performance in Cs2O Crystal

Abstract

In this work, first principles DFT calculations has been employed with anharmonic phonon scatter theory and Boltzmann transport method to perform a exhaustive study on the thermoelectric properties as electronic and phonon transport of layered Cs2O crystal. The results indicate that Cs2O crystal represents a flat-and-dispersive type band structure, which returns a high power factor. In the other hand, low lattice thermal conductivity is discovered in Cs2O semiconductor, combined with its high power factor, the Cs2O crystal is considered a promising thermoelectric material. It is demonstrated that p-type Cs2O could be optimized to exhibit outstanding thermoelectric performance with a maximum ZT value of 0.71 at 500K. Explored by density functional theory calculations, the high ZT value is due to its high Seebeck coefficient S, high electrical conductivity , and low lattice thermal conductivity .