Effect of Te Doping on Thermoelectric Property of SryCo4Sb12-xTex Compounds

Skutterudite compounds, SryCo4Sb12-xTex, were synthesized by melting method and SPS method, the thermal and electrical properties were measured in the temperature range from 300K to 850K. Both carrier concentration and electrical conductivity of SryCo4Sb12-xTex compounds are higher than those of the matrix with similar Sr filling fraction. The magnitude of Seebeck coefficient is increased in comparison with that of matrix with similar carrier concentration, especially at high temperature. Lattice thermal conductivity is further decreased due to the extra electron-phonon scattering mode introduced by Te doping. The maximum ZT value of 1.0 is obtained for Sr0.18Co4Sb11.95Te0.05 at 850K, which is improved by 35% compared with that of Sr0.17Co4Sb12.