ICT2014 Abstracts

To study the effect of Te-Se-S triple doping on the thermoelectric properties of CoSb₃ skutterudite, we have prepared dense samples of Co₄Sb_11.3Te_0.65Se_0.2-xS_x（0≤x≤0.2）by the spark plasma sintering technique. The bulk samples have the typical characteristics of diffraction peaks like the pure CoSb₃, which indicate that Te, Se and S could enter into the lattice structure combining the electron microprobe analysis. Compared with the undoped or Te-doped CoSb₃ compounds, the triple-doped samples possess significantly suppressed lattice thermal conductivity, which is mainly attributed to the greatly increased point defect scattering. We also found that S is superior to Se in the aspect of decreasing the lattice thermal conductivity when the Te-doped fraction is stable at 0.65. The lowest lattice thermal conductivity at room temperature is about 1.88 Wm^-1K^-2. The highest ZT value of  1.29 is obtained at 800 K for the x = 0.2 sample, which is 15% higher than that of  x = 0.0 sample.

Key words: Te-Se-S doping , skutterudite, thermoelectric properties