n‐type Mg₃Sb_1.5Bi_0.5 has recently been discovered to be a promising thermoelectric material, yet the effective n‐type dopants are mainly limited to the chalcogens. This may be attributed to the limited chemical insight into the effects from different n‐type dopants. By comparing the effects of different chalcogen dopants Q (Q = S, Se, and Te) on thermoelectric properties, it is found that the chalcogen dopants Q become more efficient with decreasing electronegativity difference between Q and Mg, which is mainly due to the increasing carrier concentration and mobility. Using density functional theory calculations, it is shown that the improving carrier concentration originates from the increasing doping limit induced by the stabilizing extrinsic defect. Moreover, the increasing electron mobility with decreasing electronegativity difference between Q and Mg is attributed to the smaller effective mass resulting from the enhancing chemical bond covalency, which is supported by the decreasing theoretical density of states. According to the above trends, a simple guiding principle based on electronegativity is proposed to shed new light on n‐type doping in Zintl antimonides.

中文翻译：

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n型Mg3Sb2基热电材料中通过硫族元素掺杂调节电输运性质的新见解

n型Mg ₃ Sb _1.5 Bi _0.5近年来，人们已经发现它是一种很有前途的热电材料，但是有效的n型掺杂剂主要限于硫族元素。这可能归因于对不同n型掺杂剂影响的化学认识有限。通过比较不同硫族元素掺杂剂Q（Q = S，Se和Te）对热电性能的影响，发现硫族元素掺杂剂Q随着Q和Mg之间电负性差异的减小而变得更有效，这主要是由于增加载流子浓度和迁移率。使用密度泛函理论计算表明，提高的载流子浓度源自稳定的外在缺陷引起的掺杂极限的增加。而且，电子迁移率随Q和Mg之间电负性差异的减小而增加，这归因于化学键价的提高而导致的有效质量较小，而有效态的理论密度降低也证明了这一点。根据上述趋势，提出了一种基于电负性的简单指导原则，为Zintl锑化物的n型掺杂提供了新的思路。