One-dimensional defects in graphene have a strong influence on its physical properties, such as electrical charge transport and mechanical strength. With enhanced chemical reactivity, such defects may also allow us to selectively functionalize the material and systematically tune the properties of graphene. Here we demonstrate the selective deposition of metal at chemical vapour deposited graphene's line defects, notably grain boundaries, by atomic layer deposition.
View Article and Find Full Text PDFThe reaction of phenyl isocyanate (PIC) following adsorption at the Ge(100)-2 × 1 surface has been investigated both experimentally and theoretically by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, quantum chemical calculations, and molecular dynamics simulations. PIC initially adsorbs by [2 + 2] cycloaddition across the C═N bond of the isocyanate, as previously reported, but this initial product converts to a second product on the time scale of minutes at room temperature. The experimental and theoretical results show that the second product formed is phenylnitrene (C6H5N) covalently bonded to the germanium surface via a single Ge-N bond.
View Article and Find Full Text PDFThe structural characteristics of fully-hydrogenated carbon and boron nitride mono- and multilayer slabs, together with nanotubes derived from the slabs, are investigated mainly by means of periodic local second-order Møller-Plesset perturbation (LMP2) calculations and the results are compared with Hartree-Fock (HF), density functional theory (DFT), and dispersion function-augmented DFT (DFT-D) obtained ones. The investigated systems are structurally analogous to (111) and (110) slabs of diamond, where the hydrogenated (111) slab of diamond corresponds to the experimentally known graphane. Multilayering of monolayers and nanotubes is energetically favorable at the LMP2 level for both C and BN, while HF and DFT are not able to reproduce this behavior for CH systems.
View Article and Find Full Text PDFGrowth characteristics of zinc sulfide thin films deposited from dialkylzinc and H(2)S reactants by the atomic layer deposition technique have been investigated by quantum chemical methods. The steady-state growth of the films was simulated by studying the reaction of the Zn precursor with the hydrogenated sulfur-terminated (111) surface of zincblende ZnS and then by investigating the chemisorption of hydrogen sulfide on the surface formed by the metal exposure. The behavior of the dissociatively chemisorbed Zn precursors on the growth surface is of particular significance for the film deposition process, since the film growth is limited by the Zn deposition step.
View Article and Find Full Text PDFThe structural characteristics of perhydrogenated carbon and boron nitride nanotubes are determined by means of quantum chemical calculations. Two families of nanotubes are systematically studied for both carbon and boron nitride, the nanotubes being derived from the perhydrogenated (110) and (111) sheets of diamond and cubic boron nitride. Single-walled perhydrogenated carbon nanotubes prefer structures analogous to the (111) sheet.
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