Migration of gold atoms in graphene ribbons: Role of the edges

Zhang, Wei; Sun, Litao; Xu, Zijian; Krasheninnikov, Arkady V.; Huai, Ping; Zhu, Zhiyuan; Banhart, Florian

doi:10.1103/physrevb.81.125425

Cited by 47 publications

(41 citation statements)

References 33 publications

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“…These edgetrapped Pt atoms are a strong evidence of edge-doping, which is critical to graphene nanoribbon devices. 4,25,38 Figure 4a−c shows a typical dopant trapping process in Codoped graphene, which uncovers the proposed two-step mechanism. We observe that a vacancy traps a Co atom after some time, which confirms the theoretical predictions.…”

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confidence: 86%

Doping Monolayer Graphene with Single Atom Substitutions

et al. 2011

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Functionalized graphene has been extensively studied with the aim of tailoring properties for gas sensors, superconductors, supercapacitors, nanoelectronics, and spintronics. A bottleneck is the capability to control the carrier type and density by doping. We demonstrate that a two-step process is an efficient way to dope graphene: create vacancies by high-energy atom/ion bombardment and fill these vacancies with desired dopants. Different elements (Pt, Co, and In) have been successfully doped in the single-atom form. The high binding energy of the metal-vacancy complex ensures its stability and is consistent with in situ observation by an aberration-corrected and monochromated transmission electron microscope.

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confidence: 86%

Doping Monolayer Graphene with Single Atom Substitutions

et al. 2011

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“…Interestingly, the linear diffusion of metal atoms along the open edge of a graphene layer is also reported in [6]. As the structures of the metal influence the charge transfer between metal and graphene, understanding the interaction between metal atoms and graphene [8] at the microscopic level is highly important for optimizing the electronic properties and fabricating nanoelectronic devices.…”

Section: Introductionmentioning

confidence: 90%

Ab initio study of gold-doped zigzag graphene nanoribbons

2014

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The electronic transport properties of zigzag graphene nanoribbons (ZGNRs) through covalent functionalization of gold (Au) atoms is investigated by using non-equilibrium Green's function combined with density functional theory. It is revealed that the electronic properties of Au-doped ZGNRs vary significantly due to spin and its non-inclusion. We find that the DOS profiles of Auadsorbed ZGNR due to spin reveal very less number of states available for conduction, whereas non-inclusion of spin results in higher DOS across the Fermi level. Edge Au-doped ribbons exhibit stable structure and are energetically more favorable than the center Au-doped ZGNRs. Though the chemical interaction at the ZGNR-Au interface modifies the Fermi level, Au-adsorbed ZGNR reveals semimetallic properties. A prominent qualitative change of the I-V curve from linear to nonlinear is observed as the Au atom shifts from center toward the edges of the ribbon. Number of peaks present near the Fermi level ensures conductance channels available for charge transport in case of Au-center-substituted ZGNR. We predict semimetallic nature of the Au-adsorbed ZGNR with a high DOS peak distributed over a narrow energy region at the Fermi level and fewer conductance channels. Our calculations for the magnetic properties predict that Au functionalization leads to semiconducting nature with different band gaps for spin up and spin down. The outcomes are compared with the experimental and theoretical results available for other materials.

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“…[80][81] Recent calculations of Au atom diffusion on graphene have found a 1.4 eV barrier to migration along the sheet edge. 82 …”

Section: Cluster Calculationsmentioning

confidence: 97%

Formation Mechanism of Metal–Molecule–Metal Junctions: Molecule-Assisted Migration on Metal Defects

et al. 2015

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Activation energies E a measured from molecular exchange experiments are combined with atomic-scale calculations to describe the migration of bare Au atoms and Au-alkanethiolate species on gold nanoparticle surfaces during ligand exchange for the creation of metal-molecule-metal junctions. It is well known that Au atoms and alkanethiol-Au species can diffuse on gold with sub-1 eV barriers, and surface restructuring is crucial for self-assembled monolayer (SAM) formation, for interlinking nanoparticles and in contacting nanoparticles to electrodes. In the present work, computer simulations reveal that naturally occurring ridges and adlayers on Au(111) are etched and resculpted by migration of alkanethiolate-Au species towards high coordination kink sites at surface step edges. The calculated energy barrier E b for diffusion via step edges is 0.4-0.7 eV, close to the experimentally-measured E a of 0.5-0.7 eV. By contrast, putative migration from isolated nine-coordinated terrace sites and complete Au unbinding from the surface incur significantly larger barriers of +1 and +3 eV, respectively. Molecular van der Waals's packing energies are calculated to have negligible effect on migration barriers for typically-used molecules (length < 2.5nm), indicating that migration inside SAMs does not change the size of the migration barrier. We use the computational methodology to propose a means of creating Au nanoparticle arrays via selective replacement of citrate protector molecules by thiocyanate linker molecules on surface step sites. This work also outlines the possibility of using Au/Pt alloys as possible candidates for creation of contacts that are well-formed and long-lived, due to the superior stability of Pt interfaces against atomic migration.

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Migration of gold atoms in graphene ribbons: Role of the edges

Cited by 47 publications

References 33 publications

Doping Monolayer Graphene with Single Atom Substitutions

Doping Monolayer Graphene with Single Atom Substitutions

Ab initio study of gold-doped zigzag graphene nanoribbons

Formation Mechanism of Metal–Molecule–Metal Junctions: Molecule-Assisted Migration on Metal Defects

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