ith Se due to the higher lattice disorder (Figure 8d).After having subtracted the electronic contribution κe, κdecreased with temperature in the low-temperature range andstabilized or increased at higher temperatures, when the bipolarcontribution, κbi, became significant (Figure 9e). Above theDebye temperature, ca. 145 K for Bi2Te3,49 phonon scattering byUmklapp mechanism leads to a T−1 dependence of the latticethermal conductivity, κL. On the other hand, κbi displays anexponential dependence with temperature and the material bandgap,