Search results for "Nanoribbon"
showing 6 items of 56 documents
Bottom-Up, On-Surface-Synthesized Armchair Graphene Nanoribbons for Ultra-High-Power Micro-Supercapacitors
2020
Bottom-up-synthesized graphene nanoribbons (GNRs) with excellent electronic properties are promising materials for energy storage systems. Herein, we report bottom-up-synthesized GNR films employed as electrode materials for micro-supercapacitors (MSCs). The micro-device delivers an excellent volumetric capacitance and an ultra-high power density. The electrochemical performance of MSCs could be correlated with the charge carrier mobility within the differently employed GNRs, as determined by pump–probe terahertz spectroscopy studies.
Electronic structure trends of Möbius graphene nanoribbons from minimal-cell simulations
2014
Investigating topological effects in materials requires often the modeling of material systems as a whole. Such modeling restricts system sizes, and makes it hard to extract systematic trends. Here, we investigate the effect of M\"obius topology in the electronic structures of armchair graphene nanoribbons. Using density-functional tight-binding method and minimum-cell simulations through revised periodic boundary conditions, we extract electronic trends merely by changing cells' symmetry operations and respective quantum number samplings. It turns out that for a minimum cell calculation, once geometric and magnetic contributions are ignored, the effect of the global topology is unexpectedl…
Synthesis of Nonplanar Graphene Nanoribbon with Fjord Edges
2021
As a new family of semiconductors, graphene nanoribbons (GNRs), nanometer-wide strips of graphene, have appeared as promising candidates for next-generation nanoelectronics. Out-of-plane deformation of π-frames in GNRs brings further opportunities for optical and electronic property tuning. Here we demonstrate a novel fjord-edged GNR (FGNR) with a nonplanar geometry obtained by regioselective cyclodehydrogenation. Triphenanthro-fused teropyrene 1 and pentaphenanthro-fused quateropyrene 2 were synthesized as model compounds, and single-crystal X-ray analysis revealed their helically twisted conformations arising from the [5]helicene substructures. The structures and photophysical properties …
Theoretical Simulations on Electric Properties of CNT-Me and GNR-Me Interconnects Using Effective Media Approach
2011
Abstract To overcome disadvantages of nowadays microtechnology, a further miniaturization of electronic devices, high integration level as well as increase of both operation frequencies and power density is required, including the use of adequate materials and innovative chip interconnects. Due to their unique physical properties, especially due to a ballistic (without losses) mechanism of conductivity, carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) attract a permanently growing technological interest, for example, as promising candidates for nanointerconnects in a high-speed electronics.
Edge-stress -induced spontaneous twisting of graphene nanoribbons
2012
We present a continuum model for spontaneous twisting of graphene nanoribbons driven by compressive edge stresses. Based on a geometrically nonlinear theory of plates, we identify scaling laws for the dependence of twist angles on ribbon width. Strikingly, we find the existence of a critical width below which a ribbon will not undergo spontaneous twisting, preferring an in-plane stretching mode instead. The model predictions are shown to be in excellent qualitative and quantitative agreement with density-functional tight-binding simulations. More generally, our model provides a unifying picture of twisting in graphene nanoribbons with different edge orientations and chemical functionalizati…
Modeling the mechanical behavior of carbon nanostructures
2016
Low-dimensional nanostructures are expected to have vast number of applications in the future. Particularly large amount of research has been invested in the atomthick carbon membrane called graphene, which has become popular due to its unique electronic and mechanical properties. This thesis presents studies of the mechanical and electromechanical properties of several different types of graphene nanostructures. In addition, short detours are performed in order to study the elasticity of gold nanostructures and topology effects in graphene nanoribbons. The research is performed by using several different simulation methods. In simulations the system parameters and environment can be chosen…