| 1. |
- Tiwari, Amit Kumar, et al.
(author)
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Transition metal oxide-diamond interfaces for electron emission applications
- 2013
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In: Silicon carbide and related materials 2012. - Durnten-Zurich : Trans Tech Publications Inc.. - 9783037856246 ; , s. 761-764
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Conference paper (peer-reviewed)abstract
- Diamond surfaces with suitable adsorbed chemical species can exhibit both negative and positive electron affinities, arising from the complex electrostatic interplay between adsorbates and surface carbon atoms of diamond lattice. We present the results of density functional calculations into the energetics and the electron affinity of diamond (100) surfaces terminated with the oxides of selected transition metals. We find that for a correct stoichiometry, oxides of transition metals, such as Ti and Zn, exhibit a large negative electronic affinity of around 3 eV. The desorption of transition metal oxides is found to be highly endothermic. We therefore propose that transition metal oxides are promising for the surface coating of diamond-based electron emitters, as these exhibit higher thermal stability in comparison to the commonly used Cs-O termination, while retaining the advantage of inducing a large negative electron affinity
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| 2. |
- Tiwari, Amit K., et al.
(author)
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Ultra thin transition metal oxide coatings on diamond for thermionic applications
- 2013
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In: Proceedings of the MRS Fall Meeting Symposim, MRS Fall Meeting, 24-29 November 2012, Boston, USA. - Warrendale : Materials Research Society. ; , s. 13-18
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Conference paper (peer-reviewed)abstract
- We have investigated, using density functional simulations, the energetics and the electronic properties of oxides of selected transition metals, TMs, adsorbed onto a diamond (001) surface. We find that stoichiometric oxides of TMs, particularly Ti and Zn, influence the electron affinity of diamond strongly. The electron affinities of stoichiometric oxides of Ti and Zn are calculated to be around -3eV, significantly higher than 1.9eV of commonly used H-termination. The reactions of TMs with an oxygenated diamond are found to be highly exothermic. Based upon the energetics and the electronic properties, we propose that in the regime of ultra thin films, oxides of TMs are promising options for surface coating of diamond-based electron emitters, as these coatings are compatible with semiconductor device fabrication processes, while having the benefit of inducing a large negative electron affinity
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| 3. |
- Pinto, Helder M., et al.
(author)
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Ab initio studies of fluorine passivation on the electronic structure of the NV- defect in nanodiamond
- 2012
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In: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 12:11, s. 8589-8593
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Journal article (peer-reviewed)abstract
- We have investigated using density functional theory the effect of fluorine termination of a (001) diamond surface on the electronic energy levels of an NV- centre buried beneath the surface. We find that, like OH termination, fluorine passivates the surface and reduces the influence of the surface on the electronic properties of the NV- centre. The results have significance for the optical properties of NV- defects in nanodiamonds
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