Electronic Properties of Au-Doped Narrow Armchair Graphene Nanoribbons: A First Principle Calculations

2014 ◽  
Vol 1015 ◽  
pp. 155-158
Author(s):  
Wei Hua Wang ◽  
Cui Lan Zhao ◽  
Xin Jun Ma
Keyword(s):  
Charge Density ◽  
Valence Band ◽  
Density Of States ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Local Density ◽  
Electronic States ◽  
Electronic Energy ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene

The centre Au-doped armchair graphene nanoribbons (AGNRs) are investigated using the local density approximation based on density function theory. The charge density, electronic energy band and project density of states of centre Au-doped AGNRs are calculated. Our results indicate the charge density is transferred between C and Au atoms and mainly located on the Au atoms. The centre Au-doped AGNRs are an indirect band gap semiconductor with an energy gap of 1.046 eV. The Fermi level is located on valence band so that the AGNRs of doping Au become into degenerate semiconductor. The project density of states is calculated to reveal localization and hybridization between C-2pand Au-6s, 5delectronic states. The localization and hybridization are much stronger in the valence band. The hybridization between C-2pand Au-6pelectronic states are strongly in the conduction band.

Effects of band hybridization on electronic properties in tuning armchair graphene nanoribbons

2016 ◽  
Vol 94 (2) ◽  
pp. 218-225 ◽  
Author(s):  
M. Khatun ◽  
Z. Kan ◽  
A. Cancio ◽  
C. Nelson
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Graphene Nanoribbons ◽  
Local Density ◽  
Tight Binding ◽  
Edge States ◽  
Local Density Of States ◽  
Periodic Patterns ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene

We explore a model of armchair graphene nanoribbons tuned by functionalizing the edge states. Edge modifications are modeled by changing the electronic energy of the edge states in specific periodic patterns. The model can be considered to mimic a controlled doping process with different elements. The band structure, density of states, conductance, and local density of states are calculated, using the tight binding approach, Green’s function methodology, and the Landauer formula. The results show interesting behaviors, which are considerably different from the properties of the perfect nanoribbons. The hybridization of conducting bands with non-conducting bands, which appear perfectly flat in the perfect ribbon, opens up and modifies gaps in conductance near the Fermi level. One particular pattern of edge functionalization causes a strong, symmetric, and systematic band gap change about the Fermi level, modifying the electronic characteristics in the energy dispersion, density of states, local density of states, and conductance.

scholarly journals Strain and screening effects on field emission properties of armchair graphene nanoribbon arrays: a first-principles study

RSC Advances ◽  
2018 ◽  
Vol 8 (40) ◽  
pp. 22625-22634 ◽  
Author(s):  
Han Hu ◽  
Siow Mean Loh ◽  
Tsan-Chuen Leung ◽  
Ming-Chieh Lin
Keyword(s):  
Field Emission ◽  
First Principles ◽  
Graphene Nanoribbons ◽  
Local Density ◽  
First Principles Calculations ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene Nanoribbon ◽  
Armchair Graphene

The field screening effect on the field-emission properties of armchair graphene nanoribbons (AGNRs) under strain has been studied using first-principles calculations with local density approximation (LDA).

Electronic properties of armchair graphene nanoribbons under uniaxial strain and electric field

2018 ◽  
Vol 32 (24) ◽  
pp. 1850263 ◽  
Author(s):  
Li-Feng Jiang ◽  
Lei Xu ◽  
Jun Zhang
Keyword(s):  
Electric Field ◽  
Electronic Properties ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Uniaxial Strain ◽  
Quantum Phenomenon ◽  
Suitable Combination ◽  
Armchair Graphene Nanoribbons ◽  
Opening And Closing ◽  
Armchair Graphene

The armchair graphene nanoribbons (AGNRs) can be either semiconducting or metallic, depending on their widths. We investigate the electronic properties of AGNRs under uniaxial strain and electric field. We find that the bulk gap decreases gradually with the increase of the electric field for semiconducting case, but it cannot vanish completely in an appropriate range, which is similar to that of a single uniaxial strain. However, a suitable combination of electric field and uniaxial strain can lead to that the energy gap completely vanishes and reopens. For the metallic case, the bulk gap can display the same opening and closing behavior under an electric field and uniaxial strain. Finally, an interesting quantum phenomenon is obtained by applying a perpendicular magnetic field.

Calculations of the Electronic Structure of Vacancies in a-Si:H

1992 ◽  
Vol 291 ◽  
Author(s):  
Ariel A. Valladares ◽  
L. Enrique Sansores
Keyword(s):  
Electronic Structure ◽  
Charge Density ◽  
Density Of States ◽  
Energy Gap ◽  
Local Density ◽  
Amorphous Solids ◽  
Local Density Of States ◽  
Hydrogen Atoms ◽  
Hartree Fock ◽  
Cluster Calculations

ABSTRACTThe electronic structure of random clusters has been used in the literature as representative of the electronic structure of random solids. In this work a calculation of the local density of states (LDOS) and charge density contours for clusters of the type XSi20H28 with X an Si atom, a vacancy or 4 hydrogen atoms, has been carried out. The method used was a pseudopotential SCF Hartree-Fock and the HONDO program. It is found that the generation of a vacancy in the center of the cluster (removal of the central Si atom), introduces p-like states in the energy gap of the LDOS for the region near the center of the cluster. The saturation of the dangling bonds of the vacancy with 4 hydrogen atoms removes the states within the gap. These results are also borne out by the charge density contours, thereby reinforcing the importance of amorphous cluster calculations in the understanding of the electronic structure of amorphous solids.

scholarly journals Finding the hidden valence band of N  =  7 armchair graphene nanoribbons with angle-resolved photoemission spectroscopy

2D Materials ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 035007 ◽  
Author(s):  
Boris V Senkovskiy ◽  
Dmitry Yu Usachov ◽  
Alexander V Fedorov ◽  
Danny Haberer ◽  
Niels Ehlen ◽  
...  
Keyword(s):  
Valence Band ◽  
Graphene Nanoribbons ◽  
Photoemission Spectroscopy ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene

Tight-Binding Approximation Calculation on the Electronic Structure of Graphene and Graphene Nanoribbons

2013 ◽  
Vol 341-342 ◽  
pp. 199-203 ◽  
Author(s):  
Hong Xia Wang ◽  
Cheng Lai Yang ◽  
You Zhang Zhu ◽  
Ni Chen Yang
Keyword(s):  
Electronic Structure ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Periodic Boundary Conditions ◽  
Tight Binding Approximation ◽  
Width Direction ◽  
Armchair Graphene Nanoribbons ◽  
Approximation Calculation ◽  
Armchair Graphene

The electronic structure expression of graphene was derived using tight-binding approxi-mation method. According to periodic boundary conditions in width direction of graphene nanorib-bons wave vector, the electronic structure analytical expression of armchair graphene nanoribbons was deduced, and the energy band curve were given. The conditions of graphene nanoribbons being metal or semiconductor were obtained. The results show that when nanoribbons width meetsL=3na/2, the energy gap is zero and armchair graphene nanoribbons behave as the metallic. With the increase of the nanoribbons width, the energy gap of semiconducting nanoribbons decreases. The electronic properties of graphene nanoribbons are closely related to their geometry. The graphene nanoribbons can be modulated into metal or semiconductor with different band gap by controlling their width.

Family-dependent magnetism in atomic boron adsorbed armchair graphene nanoribbons

2019 ◽  
Vol 7 (21) ◽  
pp. 6241-6245 ◽  
Author(s):  
Wei-Wei Yan ◽  
Xiao-Fei Li ◽  
Xiang-Hua Zhang ◽  
Xinrui Cao ◽  
Mingsen Deng
Keyword(s):  
Fermi Level ◽  
Graphene Nanoribbons ◽  
Spin Splitting ◽  
Localized State ◽  
The Family ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene ◽  
Boron Adsorption

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.

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