Divacancies in Graphene and Carbon Nanotubes

Amorim, Rodrigo G.; Fazzio, A.; Antonelli, Alex; Novaes, Frederico D.; Silva, Antônio J. R. da

doi:10.1021/nl071217v

Cited by 186 publications

(135 citation statements)

References 17 publications

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“…At the relaxed structure the 1 Ag ground state is dominated by a closed shell configuration with almost negligible unpaired electron density. This stability distinguishes the double vacancy from the single vacancy defect where we have found previously 37 that even for the relaxed structure a substantial unpaired density existed primarily due to the occurrence of a dangling bond. …”

Section: Discussionmentioning

confidence: 64%

The electronic states of a double carbon vacancy defect in pyrene: a model study for graphene

Machado

Aquino

Lischka

2015

Phys. Chem. Chem. Phys.

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The electronic states occurring in a double vacancy defect for graphene nanoribbons have been calculated in detail based on a pyrene model. Extended ab initio calculations using the MR configuration interaction (MRCI) method have been performed to describe in a balanced way the manifold of electronic states derived from the dangling bonds created by initial removal of two neighboring carbon atoms from the graphene network. In total, this study took into account the characterization of 16 electronic states (eight singlets and eight triplets) considering unrelaxed and relaxed defect structures. The ground state was found to be of 1 Ag character with around

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Section: Discussionmentioning

confidence: 64%

The electronic states of a double carbon vacancy defect in pyrene: a model study for graphene

Machado

Aquino

Lischka

2015

Phys. Chem. Chem. Phys.

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“…For example, a DV, which can be referred to as a 585 defect ͑two pentagons and one octagon͒, see Fig. 18, can be transformed to a 555 777 defect, which is energetically more favorable in nanotubes with large ͑about 5 nm͒ diameters, 309 graphene, 310 and graphene ribbons. 311 The advent of high-resolution TEMs equipped with aberration correctors made it possible to achieve a resolution of better than 1 Å and directly see individual point defects in carbon systems, especially in graphene membranes.…”

Section: Vacancies In Graphene and Carbon Nanotubesmentioning

confidence: 99%

Ion and electron irradiation-induced effects in nanostructured materials

Krasheninnikov¹,

Nordlund²

2010

Journal of Applied Physics

922

591

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A common misconception is that the irradiation of solids with energetic electrons and ions has exclusively detrimental effects on the properties of target materials. In addition to the well-known cases of doping of bulk semiconductors and ion beam nitriding of steels, recent experiments show that irradiation can also have beneficial effects on nanostructured systems. Electron or ion beams may serve as tools to synthesize nanoclusters and nanowires, change their morphology in a controllable manner, and tailor their mechanical, electronic, and even magnetic properties. Harnessing irradiation as a tool for modifying material properties at the nanoscale requires having the full microscopic picture of defect production and annealing in nanotargets. In this article, we review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes. We also consider the two-dimensional nanosystem graphene due to its similarity with carbon nanotubes. We dwell on both theoretical and experimental results and discuss at length not only the physics behind irradiation effects in nanostructures but also the technical applicability of irradiation for the engineering of nanosystems.

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“…defects. [90][91][92] For large multivacancies or even a combination of DVs and SVs, the deformation of the nanotube will be large. The STS signatures associated with several close point defects or multivacancies ͑see, e.g., defect d2 in Fig.…”

Section: F Multiple Point Defectsmentioning

confidence: 99%

Modifying the electronic structure of semiconducting single-walled carbon nanotubes byAr+ion irradiation

et al. 2009

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Local controllable modification of the electronic structure of carbon nanomaterials is important for the development of carbon-based nanoelectronics. By combining density-functional theory simulations with Arion-irradiation experiments and low-temperature scanning tunneling microscopy and spectroscopy ͑STM/STS͒ characterization of the irradiated samples, we study the changes in the electronic structure of single-walled carbon nanotubes due to the impacts of energetic ions. As nearly all irradiation-induced defects look as nondistinctive hillocklike features in the STM images, we compare the experimentally measured STS spectra to the computed local density of states of the most typical defects with an aim to identify the type of defects and assess their abundance and effects on the local electronic structure. We show that individual irradiationinduced defects can give rise to single and multiple peaks in the band gap of the semiconducting nanotubes and that a similar effect can be achieved when several defects are close to each other. We further study the stability of defects and their evolution during STM measurements. Our results not only shed light on the abundance of the irradiation-induced defects in carbon nanotubes and their signatures in STS spectra but also suggest a way the STM can be used for engineering the local electronic structure of defected carbon nanotubes.

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Divacancies in Graphene and Carbon Nanotubes

Cited by 186 publications

References 17 publications

The electronic states of a double carbon vacancy defect in pyrene: a model study for graphene

The electronic states of a double carbon vacancy defect in pyrene: a model study for graphene

Ion and electron irradiation-induced effects in nanostructured materials

Modifying the electronic structure of semiconducting single-walled carbon nanotubes byAr+ion irradiation

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