The application of thermoelectrics in waste heat recovery requires high conversion efficiency, which is best achieved through the combination of progressive performance-enhancing strategies. In this study, we combined engineered doping, nanostructuring, and module fabrication in PbTe-based thermoelectrics to generate high-ZT materials along with high-efficiency modules. The use of excess Na (4%) as a p-type dopant greatly enhanced the thermoelectric power factor by generating extra charge carriers at high temperature. The addition of minute amounts of Ge (≤1%) generated nanoprecipitates, which greatly reduced the lattice thermal conductivity. An optimal ZT of ∼1.9 at ∼805 K was achieved for Pb_0.953Na_0.040Ge_0.007Te as a p-type leg, which was combined with PbTe_0.9964I_0.0036 as an n-type leg to fabricate thermoelectric modules. An exceptionally high efficiency of ∼12% for a temperature difference of 590 K was obtained in a cascade Bi₂Te₃/nanostructured PbTe module with eight p-n pairs.

热电在废热回收中的应用要求很高的转换效率，这最好通过结合渐进的性能增强策略来实现。在这项研究中，我们将基于PbTe的热电学中的工程掺杂，纳米结构和模块制造相结合，以生成高ZT材料以及高效模块。通过在高温下产生额外的电荷载流子，使用过量的Na（4％）作为p型掺杂剂可以大大提高热电功率因数。加入微量的Ge（≤1％）会生成纳米沉淀，这大大降低了晶格的导热率。Pb _0.953 Na _0.040 Ge的最佳ZT在805 K时达到1.9_将0.007 Te作为p型支脚，将其与作为n型支脚的PbTe _0.9964 I _0.0036结合，以制造热电模块。在具有8对p - n对的Bi ₂ Te ₃ /纳米结构PbTe级联模块中，对于590 K的温差，获得了约12％的极高效率。