title: Approaching the ideal elastic strain limit in silicon nanowires.
abstract: 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.
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region (SAR) 999077, China.; Centre for Advanced Structural Materials, City University of Hong Kong, Hong Kong SAR 999077, China.
authors.forename: Hongti
authors.initials: H
authors.lastname: Zhang
authors.affiliation: IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Tersoff
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region (SAR) 999077, China.; Centre of Super-Diamond and Advanced Films, City University of Hong Kong, Hong Kong SAR 999077, China.
authors.forename: Shang
authors.initials: S
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen 361005, China.
authors.forename: Huixin
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region (SAR) 999077, China.
authors.forename: Qiaobao
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region (SAR) 999077, China.
authors.forename: Kaili
authors.initials: K
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen 361005, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Centre of Super-Diamond and Advanced Films, City University of Hong Kong, Hong Kong SAR 999077, China.; Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR 999077, China.
authors.forename: Chun-Sing
authors.identifier: 0000-0001-6557-453X
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: King-Ning
authors.initials: KN
authors.lastname: Tu
authors.affiliation: Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Ju
authors.identifier: 0000-0002-7841-8058
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region (SAR) 999077, China.; Centre for Advanced Structural Materials, City University of Hong Kong, Hong Kong SAR 999077, China.; Centre of Super-Diamond and Advanced Films, City University of Hong Kong, Hong Kong SAR 999077, China.; Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China.
authors.forename: Yang
authors.identifier: 0000-0002-9280-2718
authors.initials: Y
authors.lastname: Lu
mesh_terms: D004548:Elasticity; D004581:Electronics; D036103:Nanotechnology; D053770:Nanowires / Q000737:chemistry*; D010316:Particle Size; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry*; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength
chemical_list: D012825:Silicon
keywords: Silicon nanowire; deep ultra-strength; elastic strain engineering; elasticity; ideal strength; nanomechanics; room temperature; tensile strain