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Analytical performance of 3 m and 3 m +1 armchair graphene nanoribbons under uniaxial strain.

Kang ES, Ismail R - Nanoscale Res Lett (2014)

Bottom Line: 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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electronic and Computer Engineering, Southern University College, Skudai 81310, Johor Darul Takzim, Malaysia.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

The ID-VD characteristic of uniaxial strained AGNRs compared to experimental data [28].
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Figure 7: The ID-VD characteristic of uniaxial strained AGNRs compared to experimental data [28].

Mentions: In order to validate the proposed analytical model, the MATLAB simulation results were compared with the experimental data [28] for a range of strain effect of uniaxial strained n =3 m AGNRs, as demonstrated in Figure 7. A good agreement was observed with no artificial parameters used in obtaining these curves. Significant drain current reduction in the proposed model was observed, resulting from the threshold voltage shift and total gate capacitance degradation due to quantum confinement. It should be noted that the influence of quantum confinement depends on the increment of gate-source voltage. Under VGS =1.2 V conditions, the drain current for the proposed model drops to 1.452 μA compared to the classical value. Meanwhile, for VGS =0.8 V and VGS =0.4 V, the current losses are 0.798 and 0.191 μA respectively. The energy of the microscopic particles is not constant but fluctuates around some average value due to the quantum mechanical effects. The fluctuation may introduce extra energy to pump the electrons to states with higher energy.


Analytical performance of 3 m and 3 m +1 armchair graphene nanoribbons under uniaxial strain.

Kang ES, Ismail R - Nanoscale Res Lett (2014)

The ID-VD characteristic of uniaxial strained AGNRs compared to experimental data [28].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231444&req=5

Figure 7: The ID-VD characteristic of uniaxial strained AGNRs compared to experimental data [28].
Mentions: In order to validate the proposed analytical model, the MATLAB simulation results were compared with the experimental data [28] for a range of strain effect of uniaxial strained n =3 m AGNRs, as demonstrated in Figure 7. A good agreement was observed with no artificial parameters used in obtaining these curves. Significant drain current reduction in the proposed model was observed, resulting from the threshold voltage shift and total gate capacitance degradation due to quantum confinement. It should be noted that the influence of quantum confinement depends on the increment of gate-source voltage. Under VGS =1.2 V conditions, the drain current for the proposed model drops to 1.452 μA compared to the classical value. Meanwhile, for VGS =0.8 V and VGS =0.4 V, the current losses are 0.798 and 0.191 μA respectively. The energy of the microscopic particles is not constant but fluctuates around some average value due to the quantum mechanical effects. The fluctuation may introduce extra energy to pump the electrons to states with higher energy.

Bottom Line: 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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Electronic and Computer Engineering, Southern University College, Skudai 81310, Johor Darul Takzim, Malaysia.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus