Electronic, Optical, and Thermoelectric Properties of BaFe2- xZnxAs2 (x=0,1,2) orthorhombic Polymorphs: DFT Study

Based on the calculations of density functional theory and Generalized Gradient approximation (GGA), mechanical, electronic, optical and thermoelectric properti BaFe2-xZnxAs2 (x=0,1,2) have been investigated in orthorhombic phase. For all three BaFe2-xZnxAs2 (x=0,1,2), the energy curves have an equilibrium point in terms of their volume. For x=1 and x=2, the bonds take on an ionic shape. Electronic calculations show that by applying the modified Becke-Johonsom (mBJ) approximation, the x=2 compound is converted to a ptype semiconductor with a gap of 0.11 eV. However, magnetic behavior can be seen for the other two impurities. At x=2, the band structure illustrates a direct gap. Optical diagrams display that the parts of the dielectric function exhibit strong metallic behavior for impurities x=0, 1, and also an optical gap can be detected. Moreover, the Seebeck coefficient provides that a good stability is observed in its behavior at room temperature onwards to reach the saturation limit of 200 μvK-1. Additionally, the figure of merit reaches a saturation limit in the range of 0.6 to 0.7 at this temperature range.