Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Edge Functionalization of Structurally Defined Graphene Nanoribbons for Modulating the Self-Assembled Structures.

ABSTRACT: Edge functionalization of bottom-up synthesized graphene nanoribbons (GNRs) with anthraquinone and naphthalene/perylene monoimide units has been achieved through a Suzuki coupling of polyphenylene precursors bearing bromo groups, prior to the intramolecular oxidative cyclo-dehydrogenation. High efficiency of the substitution has been validated by MALDI-TOF MS analysis of the functionalized precursors and FT-IR, Raman, and XPS analyses of the resulting GNRs. Moreover, AFM measurements demonstrated the modulation of the self-assembling behavior of the edge-functionalized GNRs, revealing that GNR-PMI formed an intriguing rectangular network. This result suggests the possibility of programming the supramolecular architecture of GNRs by tuning the functional units.

SUBMITTER: Keerthi A

PROVIDER: S-EPMC5860787 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Edge Functionalization of Structurally Defined Graphene Nanoribbons for Modulating the Self-Assembled Structures.

Keerthi Ashok A Radha Boya B Rizzo Daniele D Lu Hao H Diez Cabanes Valentin V Hou Ian Cheng-Yi IC Beljonne David D Cornil Jérôme J Casiraghi Cinzia C Baumgarten Martin M Müllen Klaus K Narita Akimitsu A

Journal of the American Chemical Society 20171109 46

Edge functionalization of bottom-up synthesized graphene nanoribbons (GNRs) with anthraquinone and naphthalene/perylene monoimide units has been achieved through a Suzuki coupling of polyphenylene precursors bearing bromo groups, prior to the intramolecular oxidative cyclo-dehydrogenation. High efficiency of the substitution has been validated by MALDI-TOF MS analysis of the functionalized precursors and FT-IR, Raman, and XPS analyses of the resulting GNRs. Moreover, AFM measurements demonstrate ...[more]

PMID: 29098859

Similar Datasets

Self-assembled functionalized graphene nanoribbons from carbon nanotubes.

Project description:Graphene nanoribbons (GNR) were generated in ethanol solution by unzipping pyrrolidine-functionalized carbon nanotubes under mild conditions. Evaporation of the solvent resulted in regular few-layer stacks of graphene nanoribbons observed by transmission electron microscopy (TEM) and X-ray diffraction. The experimental interlayer distance (0.49-0.56?nm) was confirmed by computer modelling (0.51?nm). Computer modelling showed that the large interlayer spacing (compared with graphite) is due to the presence of the functional groups and depends on their concentration. Stacked nanoribbons were observed to redissolve upon solvent addition. This preparation method could allow the fine-tuning of the interlayer distances by controlling the number and/or the nature of the chemical groups in between the graphene layers.

| S-EPMC4420582 | biostudies-literature

Edge Contacts to Atomically Precise Graphene Nanoribbons.

Project description:Bottom-up-synthesized graphene nanoribbons (GNRs) are an emerging class of designer quantum materials that possess superior properties, including atomically controlled uniformity and chemically tunable electronic properties. GNR-based devices are promising candidates for next-generation electronic, spintronic, and thermoelectric applications. However, due to their extremely small size, making electrical contact with GNRs remains a major challenge. Currently, the most commonly used methods are top metallic electrodes and bottom graphene electrodes, but for both, the contact resistance is expected to scale with overlap area. Here, we develop metallic edge contacts to contact nine-atom-wide armchair GNRs (9-AGNRs) after encapsulation in hexagonal boron-nitride (h-BN), resulting in ultrashort contact lengths. We find that charge transport in our devices occurs via two different mechanisms: at low temperatures (9 K), charges flow through single GNRs, resulting in quantum dot (QD) behavior with well-defined Coulomb diamonds (CDs), with addition energies in the range of 16 to 400 meV. For temperatures above 100 K, a combination of temperature-activated hopping and polaron-assisted tunneling takes over, with charges being able to flow through a network of 9-AGNRs across distances significantly exceeding the length of individual GNRs. At room temperature, our short-channel field-effect transistor devices exhibit on/off ratios as high as 3 × 105 with on-state current up to 50 nA at 0.2 V. Moreover, we find that the contact performance of our edge-contact devices is comparable to that of top/bottom contact geometries but with a significantly reduced footprint. Overall, our work demonstrates that 9-AGNRs can be contacted at their ends in ultra-short-channel FET devices while being encapsulated in h-BN.

| S-EPMC10569104 | biostudies-literature

Modulating Electronic Structures of Armchair GaN Nanoribbons by Chemical Functionalization under an Electric Field Effect.

Project description:The electronic and magnetic properties of oxygen- and sulfur-passivated one-dimensional armchair GaN nanoribbons (A-GaNNRs) are revealed using both first-principles density-functional theory and ab initio molecular dynamics simulations. We explore that an applied external electric field can further modulate the electronic properties of both pristine and passivated A-GaNNRs, thus changing their properties (semiconducting-metallic-half-metallic). A-GaNNRs of 0.9-3.1 nm width are subjected to further investigations, which reveal that sulfur termination transforms pristine A-GaNNRs from direct into indirect band gap semiconductors, without affecting their nonmagnetic nature. On the other hand, oxygen passivation introduces spin-polarized behavior with a finite magnetic moment. Magnetism characteristics in both bare and sulfur-passivated A-GaNNRs are induced by applying a critical electric field along the direction of NR width. The passivated A-GaNNRs are more stable compared to bare ones, while sulfur-passivated A-GaNNRs exhibit higher stability at higher temperatures (>500 °C). Thus, our results suggest that A-GaNNRs can be used in a broad range of electronic, optoelectronic, and spintronic applications.

| S-EPMC6977195 | biostudies-literature

Geometric and electronic properties of edge-decorated graphene nanoribbons.

Project description:Edge-decorated graphene nanoribbons are investigated with the density functional theory; they reveal three stable geometric structures. The first type is a tubular structure formed by the covalent bonds of decorating boron or nitrogen atoms. The second one consists of curved nanoribbons created by the dipole-dipole interactions between two edges when decorated with Be, Mg, or Al atoms. The final structure is a flat nanoribbon produced due to the repulsive force between two edges; most decorated structures belong to this type. Various decorating atoms, different curvature angles, and the zigzag edge structure are reflected in the electronic properties, magnetic properties, and bonding configurations. Most of the resulting structures are conductors with relatively high free carrier densities, whereas a few are semiconductors due to the zigzag-edge-induced anti-ferromagnetism.

| S-EPMC4133719 | biostudies-literature

Selective electrochemical functionalization of the graphene edge.

Project description:We present a versatile and simple method using electrochemistry for the exclusive functionalization of the edge of a graphene monolayer with metal nanoparticles or polymeric amino groups. The attachment of metal nanoparticles allows us to exploit surface-enhanced Raman scattering to characterize the chemistry of both the pristine and the functionalized graphene edge. For the pristine patterned graphene edge, we observe the typical edge-related modes, while for the functionalized graphene edge we identify the chemical structure of the functional layer by vibrational fingerprinting. The ability to obtain single selectively functionalized graphene edges routinely on an insulating substrate opens an avenue for exploring the effect of edge chemistry on graphene properties systematically.

| S-EPMC6346287 | biostudies-literature

Detecting the spin-polarization of edge states in graphene nanoribbons.

Project description:Low dimensional carbon-based materials can show intrinsic magnetism associated to p-electrons in open-shell π-conjugated systems. Chemical design provides atomically precise control of the π-electron cloud, which makes them promising for nanoscale magnetic devices. However, direct verification of their spatially resolved spin-moment remains elusive. Here, we report the spin-polarization of chiral graphene nanoribbons (one-dimensional strips of graphene with alternating zig-zag and arm-chair boundaries), obtained by means of spin-polarized scanning tunnelling microscopy. We extract the energy-dependent spin-moment distribution of spatially extended edge states with π-orbital character, thus beyond localized magnetic moments at radical or defective carbon sites. Guided by mean-field Hubbard calculations, we demonstrate that electron correlations are responsible for the spin-splitting of the electronic structure. Our versatile platform utilizes a ferromagnetic substrate that stabilizes the organic magnetic moments against thermal and quantum fluctuations, while being fully compatible with on-surface synthesis of the rapidly growing class of nanographenes.

| S-EPMC10590394 | biostudies-literature

Helical edge states and edge-state transport in strained armchair graphene nanoribbons.

Project description:A helical type edge state, which is generally supported only on graphene with zigzag boundaries, is found to also appear in armchair graphene nanoribbons in the presence of intrinsic spin-orbit coupling and a suitable strain. At a critical strain, there appears a quantum phase transition from a quantum spin Hall state to a trivial insulator state. Further investigation shows that the armchair graphene nanoribbons with intrinsic spin-orbit coupling, Rashba spin-orbit coupling, effective exchange fields and strains also support helical-like edge states with a unique spin texture. In such armchair graphene nanoribbons, the spin directions of the counterpropogating edge states on the same boundary are always opposite to each other, while is not conserved and the spins are canted away from the -direction due to the Rashba spin-orbit coupling, which is different from the case of the zigzag graphene nanoribbons. Moreover, the edge-state energy gap is smaller than that in zigzag graphene nanoribbons, even absent in certain cases.

| S-EPMC5562773 | biostudies-other

Atomically precise edge chlorination of nanographenes and its application in graphene nanoribbons.

Project description:Chemical functionalization is one of the most powerful and widely used strategies to control the properties of nanomaterials, particularly in the field of graphene. However, the ill-defined structure of the present functionalized graphene inhibits atomically precise structural characterization and structure-correlated property modulation. Here we present a general edge chlorination protocol for atomically precise functionalization of nanographenes at different scales from 1.2 to 3.4?nm and its application in graphene nanoribbons. The well-defined edge chlorination is unambiguously confirmed by X-ray single-crystal analysis, which also discloses the characteristic non-planar molecular shape and detailed bond lengths of chlorinated nanographenes. Chlorinated nanographenes and graphene nanoribbons manifest enhanced solution processability associated with decreases in the optical band gap and frontier molecular orbital energy levels, exemplifying the structure-correlated property modulation by precise edge chlorination.

| S-EPMC3831289 | biostudies-literature

Spatially resolved electronic structures of atomically precise armchair graphene nanoribbons.

Project description:Graphene has attracted much interest in both academia and industry. The challenge of making it semiconducting is crucial for applications in electronic devices. A promising approach is to reduce its physical size down to the nanometer scale. Here, we present the surface-assisted bottom-up fabrication of atomically precise armchair graphene nanoribbons (AGNRs) with predefined widths, namely 7-, 14- and 21-AGNRs, on Ag(111) as well as their spatially resolved width-dependent electronic structures. STM/STS measurements reveal their associated electron scattering patterns and the energy gaps over 1 eV. The mechanism to form such AGNRs is addressed based on the observed intermediate products. Our results provide new insights into the local properties of AGNRs, and have implications for the understanding of their electrical properties and potential applications.

| S-EPMC3523290 | biostudies-literature

Topological phase transition in chiral graphene nanoribbons: from edge bands to end states.

Project description:Precise control over the size and shape of graphene nanostructures allows engineering spin-polarized edge and topological states, representing a novel source of non-conventional π-magnetism with promising applications in quantum spintronics. A prerequisite for their emergence is the existence of robust gapped phases, which are difficult to find in extended graphene systems. Here we show that semi-metallic chiral GNRs (chGNRs) narrowed down to nanometer widths undergo a topological phase transition. We fabricated atomically precise chGNRs of different chirality and size by on surface synthesis using predesigned molecular precursors. Combining scanning tunneling microscopy (STM) measurements and theory simulations, we follow the evolution of topological properties and bulk band gap depending on the width, length, and chirality of chGNRs. Our findings represent a new platform for producing topologically protected spin states and demonstrate the potential of connecting chiral edge and defect structure with band engineering.

| S-EPMC8452617 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data