We report on studies of electronic properties and scanning tunneling microscopy (STM) of the most common configurations of nitrogen- or boron-doped graphene and carbon nanotubes using density functional theory. Charge transfer, shift of the Fermi level, and localized electronic states are analyzed as a function of the doping configurations and concentrations. The theoretical STM images show common fingerprints for the same doping type for graphene, and metallic or semiconducting nanotubes. In particular, nitrogen is not imaged in contrast to boron. STM patterns are mainly shaped by local density of states of the carbon atoms close to the defect. STM images are not strongly dependent on the bias voltage when scanning the defect directly. However, the scanning of the defect-free side of the tube displays a perturbation compared to the pristine tube depending on the applied bias.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/nn1002425 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Non-monotonic Variation of Potential-dependent Surface Diffusion at Electrochemical Interfaces in the Presence of Coadsorbates.
Angew Chem Int Ed Engl
January 2025
University of Kiel, Physics, Olshausenstr. 40, 24098, Kiel, GERMANY.
The influence of coadsorbed ions on adsorbate diffusion, an inherent effect at solid-liquid interfaces, was studied for adsorbed sulfur on Ag(100) electrodes in the presence of bromide or iodide. Quantitative in situ high-speed scanning tunnelling microscopy (video-STM) measurements were performed both in the potential regime of the c(2×2) halide adlayer at its saturation coverage and in the regime of a disordered adlayer where the halide coverage increases with potential. These studies reveal a surprising non-monotonic potential dependence of Sad diffusion with an initial increase with halide coverage, followed by a decrease upon halide adlayer ordering into the c(2×2) structure.
View Article and Find Full Text PDFHydride Formation and Decomposition on Cu(111) in HClO.
J Am Chem Soc
January 2025
Materials Science and Engineering Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States.
Cu electrodeposition and the electrocatalysis of hydrogenation reactions thereupon involve significant interactions with adsorbed hydrogen. Electrochemical mass spectrometry (EC-MS) is used to explore the formation and decomposition of surface hydride on Cu(111) in 0.1 mol L HClO.
View Article and Find Full Text PDFGermanium nanocrystal non-volatile memory devices: fabrication, charge storage mechanism and characterization.
Nanoscale
January 2025
Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583.
The widespread proliferation and increasing use of portable electronic devices and wearables, and the recent developments in artificial intelligence and internet-of-things, have fuelled the need for high-density and low-voltage non-volatile memory devices. Nanocrystal memory, an emergent non-volatile memory (NVM) device that makes use of the Coulomb blockade effect, can potentially result in the scaling of the tunnel dielectric layer to a very small thickness. Since the nanocrystals are electrically isolated, potential charge leakage paths localized defects in the thin tunnel dielectric can be substantially reduced, unlike that in a continuous polysilicon floating gate structure.
View Article and Find Full Text PDFSynthesis and Characterization of a Non-planar Cyclophenylene on Au(111).
Chemistry
January 2025
Centro de Investigacion en Nanomateriales y Nanotecnologia, -, 33940, El Entrego, SPAIN.
We report the surface-assisted synthesis of a non-planar cyclophenylene derivative containing four meta- and two para- connected phenylene moieties on Au(111), via hierarchical Ullmann coupling of a 1,10-dibrominated angular [3]phenylene and subsequent C-C bond cleavage at the four-membered rings. Scanning tunneling microscopy and spectroscopy (STM/STS) were used for the characterization of its chemical structure and electronic properties. Density functional theory (DFT) calculations support the experimental observations.
View Article and Find Full Text PDFExtracellular Vesicles and Tunnelling Nanotubes as Mediators of Prostate Cancer Intercellular Communication.
Biomolecules
December 2024
Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia.
Prostate cancer (PCa) pathogenesis relies on intercellular communication, which can involve tunnelling nanotubes (TNTs) and extracellular vesicles (EVs). TNTs and EVs have been reported to transfer critical cargo involved in cellular functions and signalling, prompting us to investigate the extent of organelle and protein transfer in PCa cells and the potential involvement of the androgen receptor. Using live cell imaging microscopy, we observed extensive formation of TNTs and EVs operating between PCa, non-malignant, and immune cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!