Abstract We show a significant increase in thermoelectric figure-of-merit ZTmax from 0.7 of the normally doped Mg2Sn0.99Sb0.01 to 1.2 of the self-compensatively doped Mg1.94Sn0.8Sb0.2, which corresponds to a 70% enhancement. We provide a thermodynamic equilibrium energy criterion that explains the formation of compensation defects, and non-equilibrium transport criterion that is relative to the self-compensation defects to boost the thermoelectric performance, i.e. the normalized change of material parameter ΔB/Bpure. Based on the theoretical basis of alloying scattering related to the electrons and phonons, we discuss the analytical optimized fraction of the dopants or the self-compensation vacancy in two cases, respectively. Our work provides a new theoretical guideline for the design of novel thermoelectric materials through the defects engineering, especially the self-compensation defects.

中文翻译：

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通过自补偿空位增强 Mg2Sn 热电性能的热力学判据

摘要 我们显示热电品质因数 ZTmax 从正常掺杂的 Mg2Sn0.99Sb0.01 的 0.7 显着增加到自补偿掺杂的 Mg1.94Sn0.8Sb0.2 的 1.2，这对应于 70% 的增强。我们提供了解释补偿缺陷形成的热力学平衡能量准则，以及与自补偿缺陷相关的非平衡输运准则，以提高热电性能，即材料参数 ΔB/Bpure 的归一化变化。基于与电子和声子相关的合金化散射的理论基础，我们分别讨论了两种情况下掺杂剂的分析优化分数或自补偿空位。