Synergistic performance of thermoelectric and mechanical in nanotwinned high-entropy semiconductors AgMnGePbSbTe5

• Main Authors: Ma, Zheng, Luo, Yubo, Dong, Jinfeng, Liu, Yukun, Zhang, Dan, Li, Wang, Li, Chengjun, Wei, Yingchao, Jiang, Qinghui, Li, Xin, Yin, Huabing, Dravid, Vinayak P., Zhang, Qiang, Chen, Shaoping, Yan, Qingyu, Yang, Junyou, Kanatzidis, Mercouri G.
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2024
• Subjects: Engineering; High entropy semiconductor; Nanotwinned
• Online Access: https://hdl.handle.net/10356/181051
• Institution: Nanyang Technological University

Introducing nanotwins in thermoelectric materials represents a promising approach to achieving such a synergistic combination of thermoelectric properties and mechanical properties. By increasing configurational entropy, a sharply reduced stacking fault energy in a new nanotwinned high-entropy semiconductor AgMnGePbSbTe5 is reached. Dense coherent nanotwin boundaries in this system provide an efficient phonon scattering barrier, leading to a high figure of merit ZT of ≈2.46 at 750 K and a high average ZT of ≈1.54 (300-823 K) with the presence of Ag2Te nanoprecipitate in the sample. More importantly, owing to the dislocation pinning caused by coherent nanotwin boundaries and the chemical short-range disorder caused by the high configurational entropy effect, AgMnGePbSbTe5 also exhibits robust mechanical properties, with flexural strength of 82 MPa and Vickers hardness of 210 HV.