Approaching the ideal elastic strain limit in silicon nanowires

• Main Authors: Zhang, H. (Author), Tersoff, J. (Author), Xu, S. (Author), Chen, H. (Author), Zhang, Q. (Author), Zhang, K. (Author), Yang, Y. (Author), Lee, C.-S (Author), Tu, K.-N (Author), Lu, Y. (Author), Li, James (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering (Contributor), Massachusetts Institute of Technology. Department of Nuclear Science and Engineering (Contributor)
• Format: Article
• Language: English
• Published: American Association for the Advancement of Science (AAAS), 2018-02-15T16:11:13Z.
• Subjects: Article
• Online Access: Get fulltext

 Achieving high elasticity for silicon (Si) nanowires, one of the most important and versatile building blocks in nanoelectronics, would enable their application in flexible electronics and bio-nano interfaces. We show that vapor-liquid-solid-grown single-crystalline Si nanowires with diameters of ~100 nm can be repeatedly stretched above 10% elastic strain at room temperature, approaching the theoretical elastic limit of silicon (17 to 20%). A few samples even reached ~16% tensile strain, with estimated fracture stress up to ~20 GPa. The deformations were fully reversible and hysteresis-free under loading-unloading tests with varied strain rates, and the failures still occurred in brittle fracture, with no visible sign of plasticity. The ability to achieve this "deep ultra-strength" for Si nanowires can be attributed mainly to their pristine, defect-scarce, nanosized single-crystalline structure and atomically smooth surfaces. This result indicates that semiconductor nanowires could have ultra-large elasticity with tunable band structures for promising "elastic strain engineering" applications.