Ultrasoft silicon nanomembranes: thickness-dependent effective elastic modulus
| Autor: | Yohei Hagiwara, Ashwini Ann Davidson, Byeori Han, Ajit K. Katiyar, Seonwoo Lee, Takahiro Shimada, Yun Hwangbo, Takayuki Kitamura, Houk Jang, Jong Hyun Ahn, Hiroyuki Hirakata |
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| Rok vydání: | 2019 |
| Předmět: |
Thickness dependent
Work (thermodynamics) Materials science Silicon business.industry Modulus chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Semiconductor chemistry Optoelectronics General Materials Science Nanometre 0210 nano-technology business Elastic modulus Nanoscopic scale |
| Zdroj: | Nanoscale. 11(32) |
| ISSN: | 2040-3372 |
| Popis: | For decades, silicon (Si) has been widely used for the mass production of microelectronic circuits. Recently, as the thickness has been reduced to the nanometer scale, its application has expanded to various fields, including flexible and transparent 2D semiconductors. For the reliable and reproducible operation of such large flexible and transparent devices, obtaining precise information about the mechanical properties of low dimensional Si is crucial. Here, we demonstrate that a 2 nm-thick Si nanomembrane (NM) exhibits an extremely low Young's modulus of 3.25 GPa, a two-order smaller value than that of the bulk counterpart. Our systematic measurement of thickness-controlled Si NMs reveals the existence of significant size effect: The effective modulus rapidly changes from 180 GPa to 3.25 GPa under 25 nm to 2 nm thickness reduction. Our theoretical modeling successfully provides physical insight into the unique stiff-to-soft transition and extremely low modulus. We further demonstrate that the modulus of Si NMs can be tailored precisely via the control of surface morphology of membrane. This work therefore provides a comprehensive picture of how and why originally hard & stiff Si deforms so softly in the ultrathin 2D geometry, and proposes a new strategy to design the mechanical properties at nanoscale dimensions. |
| Databáze: | OpenAIRE |
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