Electronic and thermoelectric properties of YbMg2X2 (X = P, As, Sb, Bi) zintl compounds by first-principles method

Abstract

In this work the structural, electronic and thermoelectric properties of YbMg2X2 (X = P, As, Sb, Bi) zintl compounds were investigated comprehensively using first principles study. The electronic properties were studied using PBE GGA, TB-mBJ and hybrid (YS-PBE0) potentials. All the structural parameters of optimized structures are in harmonious agreement to the available data. The band structure study illustrates that the titled materials manifest metallic and semi metallic nature using PBE and TB-mBJ potentials while they show wide band gap semiconducting behavior by following hybrid (YS-PBE0) potential. Total density of states (TDOS) and partial density of states (PDOS) were also calculated to glimpse the contribution of orbitals of atoms in the formation of bands. Transport properties were studied by using BoltzTraP2 code employed to WIEN2k. We get enormous values of Seebeck coefficient (S), power factor (PF) and thermoelectric figure of merit (ZT) for all the samples YbMg2X2 (X = P, As, Sb, Bi). Moreover, the overwhelming transport properties for the titled compounds indicate the optimum level of carriers’ concentration which pinpoints these materials to be better thermoelectrics in the 1-2-2 zintl family.