Abstract
The conversion efficiency (zT) of thermoelectric (TE) materials has been enhanced over the last two decades, but their engineering applications are hindered by the poor mechanical properties, especially the low strength at working conditions. Here we used density functional theory (DFT) to show a strength enhancement in the TE semiconductor InSb arising from the twin boundaries (TBs). This strengthening effect leads to an 11% enhancement of the ideal shear strength in flawless crystalline InSb where this theoretical strength is considered as an upper bound on the attainable strength for a realistic material. DFT calculations reveal that the directional covalent bond rearrangements at the TB accommodating the structural mismatch lead to the anisotropic resistance against the deformation combined with the enhanced TB rigidity. This produces a strong stress response in the nanotwinned InSb. This work provides a fundamental insight for understanding the deformation mechanism of nanotwinned TE semiconductors, which is beneficial for developing reliable TE devices.
Original language | English (US) |
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Article number | 215503 |
Journal | Physical review letters |
Volume | 119 |
Issue number | 21 |
DOIs | |
State | Published - Nov 21 2017 |
Funding
This work is partially supported by National Basic Research Program of China (Grant No.973-program) under Grant No.2013CB632505, the 111 Project of China under Grant No.B07040. We acknowledge the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), as a funding source under a contract with the National Aeronautics and Space Administration (NASA), which was supported by the NASA Science Missions Directorate's Radioisotope Power Systems Technology Advancement Program. Q.A. was supported by the National Science Foundation (Grant No.CMMI-1727428) and U.S. Nuclear Regulatory Commission (NRC) under Grant No.NRC-HQ-84-15-G-0028. S.M. was supported by Act 211 Government of the Russian Federation, Contract No.02.A03.21.0011 and by the Supercomputer Simulation Laboratory of South Ural State University [40]. This work is partially supported by National Basic Research Program of China (Grant No. 973-program) under Grant No. 2013CB632505, the 111 Project of China under Grant No. B07040. We acknowledge the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), as a funding source under a contract with the National Aeronautics and Space Administration (NASA), which was supported by the NASA Science Missions Directorate’s Radioisotope Power Systems Technology Advancement Program. Q. A. was supported by the National Science Foundation (Grant No. CMMI-1727428) and U.S. Nuclear Regulatory Commission (NRC) under Grant No. NRC-HQ-84-15-G-0028. S. M. was supported by Act 211 Government of the Russian Federation, Contract No. 02.A03.21.0011 and by the Supercomputer Simulation Laboratory of South Ural State University .
ASJC Scopus subject areas
- General Physics and Astronomy