Influence of Band-Gap Opening on Ballistic Electron Transport in Bilayer Graphene and Graphene Nanoribbon FETs
Influence of Band-Gap Opening on Ballistic Electron Transport in Bilayer Graphene and Graphene Nanoribbon FETs
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DOI：
10.1109/ted.2011.2161992
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发表时间：
2011-08
影响因子：
3.1
通讯作者：
R. Sako;H. Tsuchiya;M. Ogawa
中科院分区：
文献类型：
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作者：
R. Sako;H. Tsuchiya;M. Ogawa
虽然石墨烯是一种零隙半导体，但利用纳米带结构中的量子力学约束或双层石墨烯（BLGs）中两个碳层之间的对称破缺，可以引入高达数亿电子伏特的带隙能值。然而，带隙的打开导致载流子速度的显著降低，这是由于它们的低能光谱中的带结构被调制。本文基于计算方法研究了带隙打开对石墨烯纳米带（gnr）和石墨烯纳米带（blg）中弹道电子输运的内在影响，并讨论了具有这些半导体石墨烯通道的场效应管的最终器件性能。我们已经证明，在blg - fet中增加外电场以获得更大的带隙能量会大大降低其电学特性，因为墨西哥帽结构导致电子减速；因此，gnr - fet在原理上优于blg - fet。
Although a graphene is a zero-gap semiconductor, band-gap energy values up to several hundred millielectronvolts have been introduced by utilizing quantum-mechanical confinement in nanoribbon structures or symmetry breaking between two carbon layers in bilayer graphenes (BLGs). However, the opening of a band gap causes a significant reduction in carrier velocity due to the modulation of band structures in their low-energy spectra. In this paper, we study intrinsic effects of the band-gap opening on ballistic electron transport in graphene nanoribbons (GNRs) and BLGs based on a computational approach, and discuss the ultimate device performances of FETs with those semiconducting graphene channels. We have shown that an increase in the external electric field in BLG-FETs to obtain a larger band-gap energy degrades substantially its electrical characteristics because of deacceleration of electrons due to a Mexican hat structure; therefore, GNR-FETs outperform in principle BLG-FETs.