Rationalizing and reconciling energy gaps and quantum confinement in narrow atomically precise armchair graphene nanoribbons

Carbon ◽  
2017 ◽  
Vol 116 ◽  
pp. 422-434 ◽  
Author(s):  
Aristides D. Zdetsis ◽  
E.N. Economou
2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Ying Li ◽  
Erhu Zhang ◽  
Baihua Gong ◽  
Shengli Zhang

Starting from a tight-binding model, we derive the energy gaps induced by intrinsic spin-orbit (ISO) coupling in the low-energy band structures of graphene nanoribbons. The armchair graphene nanoribbons may be either semiconducting or metallic, depending on their widths in the absence of ISO interactions. For the metallic ones, the gaps induced by ISO coupling decrease with increasing ribbon widths. For the ISO interactions, we find that zigzag graphene nanoribbons with odd chains still have no band gaps while those with even chains have gaps with a monotonic decreasing dependence on the widths. First-principles calculations have also been carried out, verifying the results of the tight-binding approximation. Our paper reveals that the ISO interaction of graphene nanoribbons is governed by their geometrical parameters.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marcelo Macedo Fischer ◽  
Leonardo Evaristo de Sousa ◽  
Leonardo Luiz e Castro ◽  
Luiz Antonio Ribeiro ◽  
Rafael Timóteo de Sousa ◽  
...  

AbstractArmchair graphene nanoribbons (AGNRs) may present intrinsic semiconducting bandgaps, being of potential interest in developing new organic-based optoelectronic devices. The induction of a bandgap in AGNRs results from quantum confinement effects, which reduce charge mobility. In this sense, quasiparticles’ effective mass becomes relevant for the understanding of charge transport in these systems. In the present work, we theoretically investigate the drift of different quasiparticle species in AGNRs employing a 2D generalization of the Su-Schrieffer-Heeger Hamiltonian. Remarkably, our findings reveal that the effective mass strongly depends on the nanoribbon width and its value can reach 60 times the mass of one electron for narrow lattices. Such underlying property for quasiparticles, within the framework of gap tuning engineering in AGNRs, impact the design of their electronic devices.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
EngSiew Kang ◽  
Razali Ismail

A unified current-voltageI-Vmodel of uniaxial strained armchair graphene nanoribbons (AGNRs) incorporating quantum confinement effects is presented in this paper. TheI-Vmodel is enhanced by integrating both linear and saturation regions into a unified and precise model of AGNRs. The derivation originates from energy dispersion throughout the entire Brillouin zone of uniaxial strained AGNRs based on the tight-binding approximation. Our results reveal the modification of the energy band gap, carrier density, and drain current upon strain. The effects of quantum confinement were investigated in terms of the quantum capacitance calculated from the broadening density of states. The results show that quantum effect is greatly dependent on the magnitude of applied strain, gate voltage, channel length, and oxide thickness. The discrepancies between the classical calculation and quantum calculation were also measured and it has been found to be as high as 19% drive current loss due to the quantum confinement. Our finding which is in good agreement with the published data provides significant insight into the device performance of uniaxial strained AGNRs in nanoelectronic applications.


2019 ◽  
Vol 7 (21) ◽  
pp. 6241-6245 ◽  
Author(s):  
Wei-Wei Yan ◽  
Xiao-Fei Li ◽  
Xiang-Hua Zhang ◽  
Xinrui Cao ◽  
Mingsen Deng

Boron adsorption induces a heavily localized state right at the Fermi level only in the family of W = 3p + 1 and thus spin-splitting occurs spontaneously.


Author(s):  
Penghui Ji ◽  
Oliver MacLean ◽  
Gianluca Galeotti ◽  
Dominik Dettmann ◽  
Giulia Berti ◽  
...  

2021 ◽  
Vol 769 ◽  
pp. 138387
Author(s):  
Gesiel G. Silva ◽  
Wiliam F. da Cunha ◽  
Marcelo L. Pereira Júnior ◽  
Luiz F. Roncaratti ◽  
Luiz A. Ribeiro

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