Effect of thallium doping on the thermal conductivity of PbTe single crystals

The thermal conductivity of thallium-doped PbTe single crystals has been measured in the temperature range 80–310 K, and the electronic and lattice (χ ph ) components of their thermal conductivity have been evaluated. The results indicate that thallium doping markedly reduces the lattice thermal conductivity of PbTe single crystals, by up to ∼29%. Heat treatment at ∼473 K reduces the density of structural defects in the crystals and increases their χ ph . Thallium doping has a significant effect on χ ph starting at 0.05 at % before annealing and starting at 0.01 at % after annealing. We have calculated the density of structural defects in the unannealed samples and the doping-induced thermal resistance Δ W of the unannealed and annealed samples. Δ W has been shown to increase with thallium content.