Ab initio calculations of structural, optical and thermoelectric properties for CoSb3 and ACo4Sb12 (A = La, Tl and Y) compounds

We present the structural, optical and thermoelectric properties of unfilled and filled CoSb3. The full potential linearized augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA) is used to investigate the optoelectronic properties and for thermoelectric properties we have used the semi-classical Boltzmann transport theory. The calculated fundamental band gap of unfilled CoSb3 at Γ symmetry point is 0.036 eV. Furthermore, filling of CoSb3 by A (A = La, Tl and Y) strongly affects the optoelectronic properties and carrier concentration of this compound. The bulk modulus of the unfilled CoSb3 is smaller than that of filled CoSb3 with Tl and Y. The results of study predict that the filling of Tl effectively enhances the efficiency of the thermoelectric properties of CoSb3.