Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
Sci Rep. 2013;3:1248. doi: 10.1038/srep01248. Epub 2013 Feb 13.
The lack of a bandgap makes bulk graphene unsuitable for room temperature transistors with a sufficient on/off current ratio. Lateral constriction of charge carriers in graphene nanostructures or vertical inversion symmetry breaking in bilayer graphene are two potential strategies to mitigate this challenge, but each alone is insufficient to consistently achieve a large enough on/off ratio (e.g. > 1000) for typical logic applications. Herein we report the combination of lateral carrier constriction and vertical inversion symmetry breaking in bilayer graphene nanoribbons (GNRs) to tune their transport gaps and improve the on/off ratio. Our studies demonstrate that the on/off current ratio of bilayer GNRs can be systematically increased upon applying a vertical electric field, to achieve a largest on/off current ratio over 3000 at room temperature.
由于缺乏能隙，体石墨烯不适合在室温下用于具有足够导通-截止电流比的晶体管。在石墨烯纳米结构中横向限制电荷载流子或在双层石墨烯中打破垂直反转对称性是两种潜在的策略，可以缓解这一挑战，但单独使用任何一种策略都不足以始终如一地实现足够大的导通-截止电流比（例如，>1000），无法满足典型逻辑应用的要求。在此，我们报告了在双层石墨烯纳米带（GNRs）中结合横向载流子限制和垂直反转对称性破坏来调节其传输能隙并提高导通-截止电流比。我们的研究表明，通过施加垂直电场，双层 GNR 的导通-截止电流比可以系统地增加，从而在室温下实现超过 3000 的最大导通-截止电流比。
