Diamond‐like compounds are a promising class of thermoelectric materials, very suitable for real applications. However, almost all high‐performance diamond‐like thermoelectric materials are p‐type semiconductors. The lack of high‐performance n‐type diamond‐like thermoelectric materials greatly restricts the fabrication of diamond‐like material‐based modules and their real applications. In this work, it is revealed that n‐type AgInSe₂ diamond‐like compound has intrinsically high thermoelectric performance with a figure of merit (zT) of 1.1 at 900 K, comparable to the best p‐type diamond‐like thermoelectric materials reported before. Such high zT is mainly due to the ultralow lattice thermal conductivity, which is fundamentally limited by the low‐frequency Ag‐Se “cluster vibrations,” as confirmed by ab initio lattice dynamic calculations. Doping Cd at Ag sites significantly improves the thermoelectric performance in the low and medium temperature ranges. By using such high‐performance n‐type AgInSe₂‐based compounds, the diamond‐like thermoelectric module has been fabricated for the first time. An output power of 0.06 W under a temperature difference of 520 K between the two ends of the module is obtained. This work opens a new window for the applications using the diamond‐like thermoelectric materials.

中文翻译：

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AgInSe2 n 型类金刚石化合物本质上具有高热电性能

类金刚石化合物是一类很有前途的热电材料，非常适合实际应用。然而，几乎所有高性能类金刚石热电材料都是p型半导体。高性能n型类金刚石热电材料的缺乏极大地限制了类金刚石材料模块的制造及其实际应用。在这项工作中，揭示了n型AgInSe ₂类金刚石化合物具有本质上高的热电性能，在900 K时品质因数（zT）为1.1，与之前报道的最好的p型类金刚石热电材料相当。如此高的zT主要归因于超低的晶格热导率，从头算晶格动力学计算证实，晶格热导率从根本上受到低频 Ag-Se“团簇振动”的限制。在 Ag 位点掺杂 Cd 显着提高了中低温范围内的热电性能。通过使用这种高性能n型AgInSe ₂基化合物，首次制造出了类金刚石热电模块。在模块两端温差520K的情况下获得0.06W的输出功率。这项工作为类金刚石热电材料的应用打开了新的窗口。