Transport properties of lightly dopedCoSb3single crystals

Abstract

CoSb 3 single crystals with low hole concentration ͑down to 10 17 cm Ϫ3 ) at 300 K and 2.6ϫ10 16 cm Ϫ3 at 90 K͒ and the highest observed value of the room-temperature hole mobility ͑the value is up to 6000 cm 2 /V s, i.e., up to about 1.8 times higher than maximum values previously reported͒ were grown. The observed temperature dependence of the Hall coefficient is explained assuming the existence of an acceptor impurity band and an additional deep acceptor level. The values of the activation energies of the shallow and deep acceptors, their concentrations, as well as the concentration of the compensating donors were calculated. It is shown that the scattering due to polar optical phonons and nonpolar optical phonons is most important in the high-temperature region. The value of the valence-band deformation potential is estimated. ͓S0163-1829͑97͒04427-5͔

Effects of Co:Sb Molar Ratio on Synthesis and Properties of Undoped CoSb3 Prepared via a Polyol Method

“…Sb is a semimetal with a relatively low ionization energy of 883.7 kJ mol À1 (compared with 496 kJ mol À1 for sodium and 2081 kJ mol À1 for neon). 9 Upon thermal excitation, Sb inclusions could ionize to donate electrons. We could assume that the free Sb impurities in the sample acted like a metal, giving up electrons to become ionized.…”

The Influence of Ni on the Transport Properties of CoSb3

“…They show not only some of the best thermoelectric characteristics, but the constituent elements are also abundant and markedly less expensive than most of the alternative skutterudite structures. CoSb 3 is a small gap semiconductor, and transport properties of this material (single crystals as well as polycrystalline specimens) have been studied extensively [7][8][9][10][11][12]. Doping is an effective way to alter the electronic properties of this skutterudite.…”

Preparation and thermoelectric properties of some phosphide skutterudite compounds

“…Most experimental studies have been conducted on Sb-based filled and unfilled skutterudite compounds. 1,2,[11][12][13][14][15][16][17][18][19][20][21] Most Sb-based filled compounds show metallic-type behavior and optimization of their thermoelectric properties, i.e., doping, is therefore somewhat difficult. Although some P-based filled and unfilled compounds have been synthesized, very limited data are available in their thermoelectric properties.…”