1. Phase interface engineering enables state-of-the-art half-Heusler thermoelectrics
- Author
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Yihua Zhang, Guyang Peng, Shuankui Li, Haijun Wu, Kaidong Chen, Jiandong Wang, Zhihao Zhao, Tu Lyu, Yuan Yu, Chaohua Zhang, Yang Zhang, Chuansheng Ma, Shengwu Guo, Xiangdong Ding, Jun Sun, Fusheng Liu, and Lipeng Hu
- Subjects
Science - Abstract
Abstract In thermoelectric, phase interface engineering proves effective in reducing the lattice thermal conductivity via interface scattering and amplifying the density-of-states effective mass by energy filtering. However, the indiscriminate introduction of phase interfaces inevitably leads to diminished carrier mobility. Moreover, relying on a singular energy barrier is insufficient for comprehensive filtration of low-energy carriers throughout the entire temperature range. Addressing these challenges, we advocate the establishment of a composite phase interface using atomic layer deposition (ALD) technology. This design aims to effectively decouple the interrelated thermoelectric parameters in ZrNiSn. The engineered coherent dual-interface energy barriers substantially enhance the density-of-states effective mass across the entire temperature spectrum while preser carrier mobility. Simultaneously, the strong interface scattering on phonons is crucial for curtailing lattice thermal conductivity. Consequently, a 40-cycles TiO2 coating on ZrNi1.03Sn0.99Sb0.01 achieves an unprecedented zT value of 1.3 at 873 K. These findings deepen the understanding of coherent composite-phase interface engineering.
- Published
- 2024
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