Theory of thin-film-mediated exfoliation of van der Waals bonded layered materials
| Autor: | Daryl C. Chrzan, Haoye Sun, Max Poschmann, James P. Mastandrea, Joel W. Ager, Hayden Taylor, Hannah M. Gramling, Yuzhi Zhou, Eric W. Sirott |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Yield (engineering) Physics and Astronomy (miscellaneous) Graphene 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Exfoliation joint law.invention symbols.namesake law 0103 physical sciences Ultimate tensile strength Monolayer symbols General Materials Science Graphite van der Waals force Composite material Thin film 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review Materials. 2 |
| ISSN: | 2475-9953 |
| DOI: | 10.1103/physrevmaterials.2.094004 |
| Popis: | Tape-mediated mechanical exfoliation of layered materials is known to require multiple exfoliation steps and to produce small, irregularly shaped monolayer samples. Recently, it has been demonstrated experimentally that deposition of a thin layer of Au on the layer to be exfoliated prior to application of the tape can yield large monolayer samples of transition metal dichalcogenides in one exfoliation step. Here the mechanism underlying these improvements is explored using atomic scale total energy calculations to study thin-film-assisted mechanical exfoliation of both ${\mathrm{MoS}}_{2}$ and graphene. This study focuses on the influence of epitaxially induced biaxial strain on the exfoliated layer and how this impacts monolayer selectivity during exfoliation. For graphite modeled with a reactive empirical bond order (REBO) plus a Lennard-Jones potential, tensile biaxial strain favors monolayer exfoliation, whereas compressive strain favors multilayer exfoliation. For graphite modeled with a more accurate registry-dependent potential and for ${\mathrm{MoS}}_{2}$ modeled with a REBO plus a Lennard-Jones potential, both compressive and tensile biaxial strains favor monolayer exfoliation. A simple model based on the interlayer potential is introduced to explain these observations, and a linear stability analysis of this model shows that the differences between the thin-film-assisted exfoliation of the considered materials arise from the stacking structure of the layered material and the details of the interlayer potential. The potential for using this simple model to screen suitable metal films for exfoliation of other 2D materials is discussed. |
| Databáze: | OpenAIRE |
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