Enhancing thermoelectric properties of (Cu,Te) co-doped skutterudite synthesized by solid-state reaction

Abstract

(Cu,Te) co-doped CoSb3-based thermoelectric compounds Cu0.3Co4Sb12-xTex were synthesized rapidly by solid-state reaction method with the sintering temperature∼923 K and holding time ∼20 min. XRD analysis showed that the prepared samples Cu0.3Co4Sb12-xTex were single-phase skutterudite structure in the range of x < 0.7 %. SEM and EDS analyses show that the sample grains are fine with an average diameter of micro-nanometer and the sample contains many micro-pores inside and the grains have a relatively uniform distribution of elements. The lattice thermal conductivity at high temperature of Cu0.3Co4Sb12-xTex (x = 0,0.3,0.5, 0.7,0.9) significantly reduced by ∼50 % when compared to the samples at room temperature due to enhanced scattering of fine grains, micro porosity and grain boundary. The maximum power factor ∼2824 μWm−1K−2 was obtained for Cu0.3Co4Sb11.5Te0.5 at 769 K and a maximum ZT value of ∼0.83 at 623 K are obtained from (Cu,Te) co-doped CoSb3 material.