Influence of Ag doping on thermoelectric properties of BiCuSeO

The effect of Ag doping on the thermoelectric properties of p-type BiCuSeO ceramics from 300 to 873 K has been investigated systematically. The electrical conductivity can be improved from 5.9 to 26.9 S cm−1 at room temperature with Ag doping. The Seebeck coefficients of Bi1−xAgxCuSeO increase monotonically with temperature in all temperature range. The thermal conductivity can be suppressed significantly due to grain refinement and nanoinclusions. A maximum power factor of 320 μW m−1 K−2 was obtained at 873 K. The combination of optimized power factor and low thermal conductivity resulted to a higher ZT value of 0.68 at 873 K for Bi0.92Ag0.08CuSeO which is about 30% higher than that of the un-doped specimen.