Alignment of semiconducting graphene nanoribbons on vicinal Ge(001)
| Autor: | Florian Göltl, Ellen A. Murray, Pierre L. Levesque, Richard Martel, Oussama Moutanabbir, Zachary J. Krebs, Michael S. Arnold, Max G. Lagally, Wyatt A. Behn, Robert M. Jacobberger, Manos Mavrikakis, Patrick Desjardins, Victor W. Brar, Matthieu Fortin-Deschênes, Donald E. Savage, Charles Smoot |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Condensed matter physics Graphene business.industry Conductance 02 engineering and technology Chemical vapor deposition 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention Crystal Semiconductor law General Materials Science 0210 nano-technology business Anisotropy Graphene nanoribbons Vicinal |
| Zdroj: | Nanoscale. 11(11) |
| ISSN: | 2040-3372 |
| Popis: | Chemical vapor deposition of CH4 on Ge(001) can enable anisotropic growth of narrow, semiconducting graphene nanoribbons with predominately smooth armchair edges and high-performance charge transport properties. However, such nanoribbons are not aligned in one direction but instead grow perpendicularly, which is not optimal for integration into high-performance electronics. Here, it is demonstrated that vicinal Ge(001) substrates can be used to synthesize armchair nanoribbons, of which ∼90% are aligned within ±1.5° perpendicular to the miscut. When the growth rate is slow, graphene crystals evolve as nanoribbons. However, as the growth rate increases, the uphill and downhill crystal edges evolve asymmetrically. This asymmetry is consistent with stronger binding between the downhill edge and the Ge surface, for example due to different edge termination as shown by density functional theory calculations. By tailoring growth rate and time, nanoribbons with sub-10 nm widths that exhibit excellent charge transport characteristics, including simultaneous high on-state conductance of 8.0 μS and a high on/off conductance ratio of 570 in field-effect transistors, are achieved. Large-area alignment of semiconducting ribbons with promising charge transport properties is an important step towards understanding the anisotropic nanoribbon growth and integrating these materials into scalable, future semiconductor technologies. |
| Databáze: | OpenAIRE |
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