Aliovalent defects are extremely effective in manipulating charge transport and atomic vibrational properties for thermoelectric enhancements. Electronic performance of thermoelectrics is optimized at a reduced Fermi level of ∼0.3, which causes the optimal carrier concentration (n_opt) to be strongly temperature dependent. This motivates a dynamic doping approach for electronic enhancements through an increase with temperature of solubility of aliovalent dopants. In addition, the defects could simultaneously act as scattering sources of phonons for reducing the lattice thermal conductivity. These effects are illustrated in this work by the temperature-dependent excess Cu solubility in n-PbTe_0.75Se_0.25 thermoelectrics, in which both carriers and dislocations are induced for regulating the electronic and phononic transport properties for a realization of an extraordinary thermoelectric figure of merit. The resultant defect structures and temperature gradient doping effects (for aliovalent solutes) could in principle open extra possibilities for optimizing charge and phonon transport properties in thermoelectrics.

铝价缺陷在控制电荷传输和原子振动特性以提高热电性能方面极为有效。在降低的费米能级（〜0.3）时优化了热电学的电子性能，这导致最佳载流子浓度（n _opt）与温度密切相关。通过随着铝价掺杂剂的溶解度的增加而增加了电子增强的动态掺杂方法。另外，这些缺陷可以同时充当声子的散射源，以降低晶格的热导率。这些作用通过温度依赖的过量Cu在n-PbTe _0中的溶解度来说明_。75 Se _{0 。25}热电学，通过感应载流子和位错来调节电子和声子的传输特性，以实现非凡的热电性能。所得的缺陷结构和温度梯度掺杂效应（对于铝价溶质而言）原则上可以为优化热电中的电荷和声子传输特性开辟额外的可能性。