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

Abstract

We report an investigation of the electronic structures and electrical transport properties of the single-filled and double-filled CoSb3 skutterudites with Ba, Yb and In atoms by density functional calculations and Boltzmann transport theory. The band structure and the density of states of single and double filled CoSb3 are calculated and discussed. Based on the results of the band structure, the temperature dependence of Seebeck coefficients, the electrical conductivity, the power factor and the carrier concentration are computed, which are generally in good agreement with the experimental data. The results indicate that the combination of (Ba, In) could greatly improve the thermoelectric properties while the combination of (In, Yb) and (Ba, Yb) would have negative effect on the power factors, due to the fact that the interaction of Yb atoms with CoSb3 would result in a reduction of the electron mobility.

Filled Skutterudites for Broadband Saturable Absorbers

“…The effective bandgap ( E g ) of In 0.2 Co 4 Sb 12 was thus estimated to be 0.32 eV, which is a value relatively smaller than the value of 0.47 eV for pure CoSb 3 , as shown in Figure a. These results were consistent with previous investigations on FSs …”

In-doped multifilled n-type skutterudites with ZT= 1.8

“…A series of In-filled skutterudites of various groups prepared with various methods followed and confirmed that indium was useful as a filler. These investigations were extended to double-filled skutterudites of In with Sn [29], with Ba [3,16,[30][31][32][33][34][35][36][37], with Tl [38], with Pb [35], with Ce [6,[39][40][41][42], with Pr [27], with Nd [21,43], with Yb [7,8,16,19,[44][45][46][47][48][49], with Lu [50], and to triple filled skutterudites of In with Ba and Ce [51], with Ba and Yb [16,52], with La and Yb [47], with Ce and Yb [41,42,53] and Ga and Tl [26]. There are also attempts to improve the TE properties by doping and/or alloying e.g.…”

High thermoelectric performance of In, Yb, Ce multiple filled CoSb3 based skutterudite compounds

“…Among skutterudites, CoSb 3 has attracted most of the attention due to its high carrier mobility, relatively low thermal conductivity, good mechanical properties, and readily available chemical constituents [5]. During the past decade, theoretical and experimental efforts have focused on optimization of this compound by identifying most effective filler species (rare earths, alkaline earths, alkali metals and the others), exploring and establishing filling fraction limits and substituting on the metal or pnicogen lattice [6][7][8][9][10][11][12][13][14][15][16][17][18]. While all these approaches brought down the thermal conductivity to a more manageable level, it nevertheless still remains well above the estimated minimum thermal conductivity of 0.31 W/m/K [19] and represents the major factor limiting the thermoelectric performance.…”