Huang Shaoji, Wei Tian-Ran, Chen Heyang, Xiao Jie, Zhu Min, Zhao Kunpeng, Shi Xun
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
ACS Appl Mater Interfaces. 2021 Dec 22;13(50):60192-60199. doi: 10.1021/acsami.1c18483. Epub 2021 Nov 30.
AgSe is a narrow band gap n-type semiconductor with high carrier mobility and low lattice thermal conductivity. It has high thermoelectric performance near room temperature. However, there is a noticeable data discrepancy for thermoelectric performance in the reported literature studies, which greatly hinders the rational understanding and potential application of this material. In this work, we comprehensively studied the homogeneity, reproducibility, and thermal stability of bulk AgSe prepared by melting and mechanical alloying methods followed by spark plasma sintering. By virtue of the atom probe topology technique, we revealed nanosized Ag- or Se-rich precipitates and micropores with Se-aggregated interfaces that have not been detected previously. The samples prepared by melting and spark plasma sintering exhibit the best homogeneity and repeatability in thermoelectric properties despite abundant nanoprecipitates. Moreover, the thermoelectric performance of AgSe is greatly improved by introducing a slight amount of excess selenium. The average can steadily reach 0.8-0.9 in the range of 300-380 K, which is among the highest values reported for AgSe-based materials. This work will rationalize the evaluation of the thermoelectric performance of AgSe.
AgSe是一种窄带隙n型半导体，具有高载流子迁移率和低晶格热导率。它在室温附近具有较高的热电性能。然而，在已报道的文献研究中，热电性能存在明显的数据差异，这极大地阻碍了对该材料的合理理解和潜在应用。在这项工作中，我们全面研究了通过熔融和机械合金化方法制备、随后进行放电等离子烧结的块状AgSe的均匀性、可重复性和热稳定性。借助原子探针断层扫描技术，我们揭示了先前未检测到的纳米尺寸富Ag或富Se沉淀物以及具有Se聚集界面的微孔。尽管存在大量纳米沉淀物，但通过熔融和放电等离子烧结制备的样品在热电性能方面表现出最佳的均匀性和可重复性。此外，通过引入少量过量的硒，AgSe的热电性能得到了极大改善。在300 - 380 K范围内，平均 可以稳定达到0.8 - 0.9，这是基于AgSe的材料所报道的最高值之一。这项工作将使对AgSe热电性能的评估更加合理。
