Random vacancy effect on the electronic transport of zigzag graphene nanoribbon using recursive Green’s function

Jamaati, Maryam; Namiranian, A.

doi:10.1016/j.commatsci.2015.01.037

Cited by 12 publications

(6 citation statements)

References 52 publications

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“…All these results support the perturbation of the defect state at rGO surface through the electrochemical reduction and oxidation, as expected . According to the previous study, this small amount of defects at the material could induce a significant change in the conductance and the resultant charge-transfer resistance at rGO microsheets …”

Section: Resultssupporting

confidence: 89%

“…Despite the challenge to reveal the meaning of the constant, this exponential decay indicates the change of electron movement through the middle paths when they reach these defects. 27 After the electrochemical oxidation of rGO microsheets for 5 and 10 min, more redox-induced defects are formed as supported by the gradual increase of I D /I G in Raman spectroscopy (Figure S4, Supporting Information). Using the perturbation ECL at the microsheets, higher ECL intensities are observed with longer electro-oxidation time (Figure S5, Supporting Information), which is ascribed to more defects at the surface accelerating the production of oxygen radicals.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 84%

“…The exactly physical meaning of α is still unknown because it is mainly controlled by multiple parameters, including the length and width of graphene and the types of defects. Despite the challenge to reveal the meaning of the constant, this exponential decay indicates the change of electron movement through the middle paths when they reach these defects …”

Section: Resultsmentioning

confidence: 99%

“…26 According to the previous study, this small amount of defects at the material could induce a significant change in the conductance and the resultant charge-transfer resistance at rGO microsheets. 27 To confirm the fluctuation of charge-transfer resistance at rGO microsheets during this short perturbation, the chargetransfer resistances at rGO microsheets after the reduction for 1 s and the following oxidation for 4 s are measured using a potential step method (Figure 2D). Generally, the classic twoelectrode system can be modelled as a simplified Randles circuit, which consists of a resistor R s (solution resistance) in series with a capacitor C dl (electric double layer) and another resistor R ct (resistance to charge transfer) in parallel.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Perturbation Electrochemiluminescence Imaging to Observe the Fluctuation of Charge-Transfer Resistance in Individual Graphene Microsheets with Redox-Induced Defects

Zhu

Jin

Jiang

et al. 2019

ACS Appl. Mater. Interfaces

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Here, the fluctuation of charge-transfer resistance in individual reduced graphene oxide (rGO) microsheets with more redox-induced defects is unprecedentedly visualized using a perturbation electrochemiluminescence (ECL) imaging. This perturbation uses a short and low potential to recover defect-covered rGO microsheets slightly and then introduces a high potential to form more redox-induced defects resulting in an increase of charge-transfer resistance. Also, these defects at rGO microsheets enhance their catalytic feature and the resultant ECL intensity so that the temporal resolution in ECL imaging is improved to 30 ms. Aided by this fast imaging approach, the exponential decrease of ECL intensity at individual graphene microsheets after the oxidation is observed, which reflects the increase of their charge-transfer resistances. Since the charge-transfer resistance at electrode surfaces is mainly affected by the conductivity of electrode materials, the result provides the dynamic information to support the reduction of the electrical conductivity in graphene with more defects.

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Section: Resultssupporting

confidence: 89%

Section: Acs Applied Materials and Interfacesmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Perturbation Electrochemiluminescence Imaging to Observe the Fluctuation of Charge-Transfer Resistance in Individual Graphene Microsheets with Redox-Induced Defects

Zhu

Jin

Jiang

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…They can induce localized states and sharp resonant states at Fermi energy 27 , which acts as scattering centers for electrons and remarkably reduces the electrical conductivity of graphene [28][29][30][31][32][33] . The conductance decreases as the defect concentration increases due to more resonant states in the transport spectrum 34,35 . However, such a suppression seems to be weakened at the charge neutrality point, leading to a minimum conductivity of 4e 2 /πh even for higher defect concentrations 36 .…”

Section: Introductionmentioning

confidence: 99%

Electrical Conductance of Graphene with Point Defects

Liu¹,

Zhou²,

Zhao³

2019

Acta Physico-Chimica Sinica

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Graphene is one of the most promising materials in nanotechnology and has attracted worldwide attention and research interest owing to its high electrical conductivity, good thermal stability, and excellent mechanical strength. Perfect graphene samples exhibit outstanding electrical and mechanical properties. However, point defects are commonly observed during fabrication which deteriorate the performance of graphene based-devices. The transport properties of graphene with point defects essentially depend on the imperfection of the hexagonal carbon atom network and the scattering of carriers by localized states. Furthermore, an in-depth understanding of the effect of specific point defects on the electronic and transport properties of graphene is crucial for specific applications. In this work, we employed density functional theory calculations and the non-equilibrium Green's function method to systematically elucidate the effects of various point defects on the electrical transport properties of graphene, including Stone-Waals and inverse Stone-Waals defects; and single and double vacancies. The electrical conductance highly depends on the type and concentration of point defects in graphene. Low concentrations of Stone-Waals, inverse Stone-Waals, and single-vacancy defects do not noticeably degrade electron transport. In comparison, DV585 induces a moderate reduction of 25%-34%, and DV55577 and DV5555-6-7777 induce significant suppression of 51%-62% in graphene. As the defect concentration increases, the electrical conductance reduces by a factor of 2-3 compared to the case of graphene monolayers with a low concentration of point defects. These distinct electrical transport behaviors are attributed to the variation of the graphene band structure; the point defects induce localized states near the Fermi level and result in energy splitting at the Dirac point due to the breaking of the intrinsic symmetry of the graphene honeycomb lattice. Double vacancies with larger defect concentrations exhibit more flat bands near the Fermi energy and more localized states in the defective region, resulting in the presence of resonant peaks close to the Fermi energy in the local density of states. This may cause resonant scattering of the carriers and a corresponding reduction of the conductance of graphene. Moreover, the partial charge densities for double vacancies and point defects with larger concentrations exhibit enhanced localization in the defective region that hinder the charge carriers. The electrical conductance shows an exponential decay as the defect concentration and energy splitting increase. These theoretical results provide important insights into the electrical transport properties of realistic graphene monolayers and will assist in the fabrication of high-performance graphene-based devices.

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Electron transport in ladder-shaped graphene cuts

Mehri

Jamaati

2019

Computational Materials Science

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Random vacancy effect on the electronic transport of zigzag graphene nanoribbon using recursive Green’s function

Cited by 12 publications

References 52 publications

Perturbation Electrochemiluminescence Imaging to Observe the Fluctuation of Charge-Transfer Resistance in Individual Graphene Microsheets with Redox-Induced Defects

Perturbation Electrochemiluminescence Imaging to Observe the Fluctuation of Charge-Transfer Resistance in Individual Graphene Microsheets with Redox-Induced Defects

Electrical Conductance of Graphene with Point Defects

Electron transport in ladder-shaped graphene cuts

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