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:
Journal Article
Journal or Publication Title:
Physical review letters
Additional Information:
© 2005 The American Physical Society
Uncontrolled Keywords:
/dk/atira/pure/researchoutput/libraryofcongress/qc
Subjects:
ID Code:
55610
Deposited By:
Deposited On:
10 Jul 2012 08:37
Refereed?:
Yes
Published?:
Published
Last Modified:
02 Jun 2020 01:30