Thermoelectric transport properties of Ni-, Pd-, and Pt- doped skutterudites with S-filling as charge compensation

Abstract

Unlike typical electronegative guest filled skutterudites, which are doped with electron donors at Sb sites to form thermodynamically stable compounds. In this study, substituting at Co sites with Ni, Pd, and Pt atoms instead of at the Sb sites was analyzed. The influence of Ni, Pd, and Pt on the electronic band structure of Ni-, Pd-, and Pt-doped skutterudites was thoroughly analyzed. The degree of band splitting caused by the doping elements was analyzed and shown to be correlated with the strength of anti-bonding between the doping elements and neighboring Sb atoms. The electronic structures in the conduction band minimum (CBM) of the S-filled skutterudites did not undergo a significant change when compared to those of the doped skutterudites. Therefore, the thermoelectric (TE) performance was optimized because of the reduction in the degree of energy band splitting due to the addition of elements ranging from Ni to Pt.