Based on the calculated results of band structures and density of states, Bi doping is used to adjust its carrier concentration in order to obtain n-type PbTe materials with high power factor. Then, coherent nanophase Cu_1.75Te is in situ formed in the n-type PbTe matrix, which can simultaneously optimize the thermal and electrical properties. As a result, at a relative lower temperature than other reports, the highest ZT value of 1.4 is obtained at 623 K for the nominal Pb_0.995Bi_0.005Te+0.86 wt% Cu_1.75Te sample. More importantly, the ZT hold a higher value in the broad temperature; especially, ZT value is about 1.2–1.4 in the temperature range of 573–773 K, which is beneficial to the significant average ZT value ZT_ave ∼ 0.9 in the temperature range of 300–773 K. These results indicate that it is an effective and feasible method to enhance the thermoelectric properties via synergistic modulation of electrical and thermal transport properties by element doping and in situ coherent nanophase.

根据能带结构和态密度的计算结果，Bi掺杂用于调节其载流子浓度，以获得高功率因数的n型PbTe材料。然后，在n型PbTe基体中原位形成相干纳米相Cu _1.75 Te，可以同时优化热学和电学性质。结果，在相对较低的温度下，对于标称Pb _0.995 Bi _0.005 Te + 0.86 wt％Cu _1.75 Te样品，在623 K下获得的最高ZT值为1.4 。更重要的是，ZT在较宽的温度下具有较高的值。特别是ZT值大约是在温度范围573-773的K，这对显著平均有益1.2-1.4 ZT值ZT _AVE 的温度范围300-773 K.的〜0.9这些结果表明，这是一种有效和可行的方法通过元素掺杂和原位相干纳米相的电和热输运性质的协同调制来增强热电性质。