Electronic Structures and Transport Properties of Single-Filled CoSb3

Abstract

Band structure and density of states (DOS) of CoSb 3 single-filled by seven kinds of atoms (R 0.125 Co 4 Sb 12 ) are calculated by the density functional method. The results for the electronic structures in turn determine the electrical transport and thermal performance. It is found that the band structure of R 0.125 Co 4 Sb 12 shows no significant changes compared with that of CoSb 3 , and the results indicate that void filling with a small quantity of R atoms does not change the bond formation in CoSb 3 . However, the partial DOS reveals that there could be interaction of Sn, Tl, In, and Yb atoms with CoSb 3 . The results for the electrical transport properties and thermal properties show that Sn, Tl, and In atoms increase the Seebeck coefficient and La, Eu, and Yb atoms are helpful for increasing the electron concentration and decreasing the thermal conductivity further. According to our calculations and Yang's principle, double-filled CoSb 3 with atomic combinations of (In, Ca), (In, Ba), (Sn, Eu), and (Sn, La) may exhibit good thermoelectric performance.

Effects of partial La filling and Sb vacancy defects on CoSb3 skutterudites

“…Early theoretical studies adopted a 100% filling fraction for computational convenience [48]. Zhou et al [49] carried out calculations for a reasonable La filling fraction of 12.5%, but without including spin polarization.…”

Thermoelectric properties of Yb-filled CoSb3 skutterudites

“…Skutterudites can satisfy the phonon-glass and electron-crystal (PGEC) concept proposed by Slack [9], and many studies have been carried out on thermoelectric skutterudites [10][11][12]. A CoSb 3 -based skutterudite has a cubic crystal structure (space group Im3) and a prototype of CoAs 3 with two voids (2a positions) at the dodecahedral cage of Sb atoms in the unit cell.…”

Electronic structure and transport properties of single and double filled CoSb3 with atoms Ba, Yb and In

“…1-5 The efficiency of a thermoelectric material is usually characterized by the dimensionless thermoelectric figure of merit ZT, defined as ZT ¼ S 2 rT/j, where r is the electrical conductivity, S the Seebeck coefficient, T the absolute temperature, and j ¼ j E þ j L the thermal conductivity with its electronic and lattice contributions. 6 The expression of ZT indicates that a good thermoelectric material should exhibit a perfect combination of high power factor (rS 2 ) and low thermal conductivity. However, it is hard to find a natural material that simultaneously possesses these two traits because the two shall result in conflicting thermoelectric material properties.…”