Kang Eng Siew, Ismail Razali
Department of Electronic and Computer Engineering, Southern University College, Skudai 81310, Johor Darul Takzim, Malaysia.
Department of Electronic Engineering, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, Skudai 81310, Johor Darul Takzim, Malaysia.
Nanoscale Res Lett. 2014 Nov 4;9(1):598. doi: 10.1186/1556-276X-9-598. eCollection 2014.
The electronic band structure and carrier density of strained armchair graphene nanoribbons (AGNRs) with widths of n =3 m and n =3 m +1 were examined using tight-binding approximation. The current-voltage (I-V) model of uniaxial strained n =3 m AGNRs incorporating quantum confinement effects is also presented in this paper. The derivation originates from energy dispersion throughout the entire Brillouin zone of uniaxial strained AGNRs based on a tight-binding approximation. Our results reveal the modification of the energy bandgap, carrier density, and drain current upon strain. Unlike the two-dimensional graphene, whose bandgap remains near to zero even when a large strain is applied, the bandgap and carrier density of AGNRs are shown to be sensitive to the magnitude of uniaxial strain. Discrepancies between the classical calculation and quantum calculation were also measured. It has been found that as much as 19% of the drive current loss is due to the quantum confinement. These analytical models which agree well with the experimental and numerical results provide physical insights into the characterizations of uniaxial strained AGNRs.
利用紧束缚近似研究了宽度为(n = 3m)和(n = 3m + 1)的应变扶手椅型石墨烯纳米带(AGNRs)的电子能带结构和载流子密度。本文还给出了考虑量子限制效应的单轴应变(n = 3m)AGNRs的电流 - 电压((I - V))模型。该推导基于紧束缚近似,源于单轴应变AGNRs在整个布里渊区的能量色散。我们的结果揭示了应变对能带隙、载流子密度和漏极电流的影响。与二维石墨烯不同,即使施加很大应变其带隙仍接近零,AGNRs的带隙和载流子密度对应变大小很敏感。还测量了经典计算和量子计算之间的差异。已发现高达19%的驱动电流损耗是由量子限制引起的。这些与实验和数值结果吻合良好的分析模型为单轴应变AGNRs的特性提供了物理见解。