Entropy Engineered Cubic n‐Type AgBiSe2 Alloy with High Thermoelectric Performance in Fully Extended Operating Temperature Range
Entropy Engineered Cubic n‐Type AgBiSe2 Alloy with High Thermoelectric Performance in Fully Extended Operating Temperature Range
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DOI：
10.1002/aenm.202003304
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发表时间：
2020-12
影响因子：
27.8
通讯作者：
Huaxing Zhu;Ting Zhao;Bin Zhang;Zibing An;Shengcheng Mao;Guoyu Wang;Xiaodong Han;Xu Lu;
中科院分区：
文献类型：
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作者：
Huaxing Zhu;Ting Zhao;Bin Zhang;Zibing An;Shengcheng Mao;Guoyu Wang;Xiaodong Han;Xu Lu;
开发高性能的n型热电材料是开发高效率热电器件的基础。AgBiSe2在立方相中表现出优异的n型TE性能，在室温下结晶为六方相，在580K以上的温度下通常经历相变到立方相。本文首次用≥9.9mol%的PbSe对其进行了熵优化，使其高温立方相从300K稳定到800K，并建立了AgBiSe2-PbSe准二元图。优化后的合金具有独特的局域扭曲立方晶格，在较宽的工作温度范围内，晶格导热系数可达0.3W m−1 K−1。在纯相立方n型(AgBiSe_2)_1PbSe_x(PbSe)_x固溶体中，获得了n型I-V-V_(12)化合物在800K时的峰值优值≈_(0.8)和平均ZT_(0.42)。这些结果为利用熵工程开发新型TE材料铺平了道路。
Developing high performance n‐type thermoelectric (TE) materials is fundamentally important for developing high efficiency TE devices. AgBiSe2, which reveals superior n‐type TE performance in a cubic phase, crystallizes in a hexagonal phase at room temperature, and typically, undergoes phase transitions to a cubic phase at a temperature above 580 K. Here, for the first time, through entropy optimization with lead‐selenides (≥9.9 mol%), the high‐temperature cubic phase of AgBiSe2 is stabilized from 300 to 800 K. Furthermore, the AgBiSe2‐PbSe pseudo‐binary diagram is established. The resultant alloys with optimized entropy possess unique local distorted cubic lattices, which contribute low lattice thermal conductivity approaching 0.3 W m−1 K−1 in extended operating temperature range. Consequently, a peak figure of merit zT value of ≈0.8 at 800 K and a record‐high average zT value of 0.42 for n‐type I‐V‐VI2 compounds are attained in pure phase cubic n‐type (AgBiSe2)1−x(PbSe)x solid solutions. These results pave the way for developing new TE materials via entropy engineering.