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Electron Emission from Diamondoids: A Diffusion Quantum Monte Carlo Study

Drummond, Neil and Williamson, A. J. and Needs, R. J. and Galli, G. (2005) Electron Emission from Diamondoids: A Diffusion Quantum Monte Carlo Study. Physical Review Letters, 95 (9). ISSN 1079-7114

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    Abstract

    We present density-functional theory (DFT) and quantum Monte Carlo (QMC) calculations designed to resolve experimental and theoretical controversies over the optical properties of H-terminated C nanoparticles (diamondoids). The QMC results follow the trends of well-converged plane-wave DFT calculations for the size dependence of the optical gap, but they predict gaps that are 1–2 eV higher. They confirm that quantum confinement effects disappear in diamondoids larger than 1 nm, which have gaps below that of bulk diamond. Our QMC calculations predict a small exciton binding energy and a negative electron affinity (NEA) for diamondoids up to 1 nm, resulting from the delocalized nature of the lowest unoccupied molecular orbital. The NEA suggests a range of possible applications of diamondoids as low-voltage electron emitters.

    Item Type: Article
    Journal or Publication Title: Physical Review Letters
    Additional Information: © 2005 The American Physical Society
    Subjects: Q Science > QC Physics
    Departments: Faculty of Science and Technology > Physics
    ID Code: 55610
    Deposited By: ep_importer_pure
    Deposited On: 10 Jul 2012 09:37
    Refereed?: Yes
    Published?: Published
    Last Modified: 09 Apr 2014 23:45
    Identification Number:
    URI: http://eprints.lancs.ac.uk/id/eprint/55610

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