uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effect of co-adsorbed dopants on initial diamond growth steps: H abstraction from an adsorbed CH3
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
2009 (English)In: Diamond and related materials, ISSN 0925-9635, Vol. 18, no 9, 1152-1156 p.Article in journal (Refereed) Published
Abstract [en]

The effect induced by a neighbouring co-adsorbed dopant on H abstraction from an adsorbed CH3 species on diamond has been investigated by using an ultra-soft pseudo-potential density functional theory (DFT) method under periodic boundary conditions. Both the (100) and (111) diamond surface orientations were considered with various types of dopants in two different hydrogenated forms; AHx (A = N, B, S, or P; X = 0 or 1 for S; X = 1 or 2 for N, B and P, and X = 2 or 3 for C). The H abstraction by gaseous radical H was found to be energetically favoured by the presence of the dopants in all of their different hydrogenated forms. For NH2, SH, or PH2, this effect is induced by a destabilisation of the diamond surface by sterical repulsions between the adsorbed growth species CH3 and the co-adsorbed dopant. For BH2 and the dopants in their radical form, the abstraction reaction is favoured due to the formation of a new covalent bond between the dopant and the co-adsorbed CH2 (product of the abstraction reaction), which strongly stabilises the surface after the abstraction process.

Place, publisher, year, edition, pages
2009. Vol. 18, no 9, 1152-1156 p.
Keyword [en]
Quantum mechanics, Diamond growth, Dopant effects
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-98004DOI: 10.1016/j.diamond.2009.02.033ISI: 000268610700018OAI: oai:DiVA.org:uu-98004DiVA: diva2:173157
Available from: 2009-02-06 Created: 2009-02-06 Last updated: 2010-07-12Bibliographically approved
In thesis
1. The Influence of Dopants on the Growth of Diamond by CVD
Open this publication in new window or tab >>The Influence of Dopants on the Growth of Diamond by CVD
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Diamond is an important material in many industrial applications (e.g., machining of hard materials, bio-electronics, optics, electronics, etc.) because of its exceptional properties such as hardness, tolerance to aggressive environments, compatibility with human tissues, and high carrier mobility. However, a highly controlled method for growing artificial high-purity diamond on a range of different substrates is needed to exploit these exceptional properties. The Chemical Vapour Deposition (CVD) method is a useful tool for this purpose, but the process still needs to be developed further to achieve better control of growth. In this context, the introduction of dopant species into the gas phase has been shown to strongly influence growth rate and surface morphology. Density Functional Theory (DFT) methods are used to deepen our atomic-level understanding of the effect of dopants on the mechanism for CVD growth on diamond. More specifically, the effect of four dopants (N, P, B and S) has been studied on the important reaction steps in the growth mechanism of diamond. Substitution of N into the diamond lattice has generally been found to disfavour critical reaction steps in the growth of the 100-face in diamond. This negative effect has been related to electron transfer from the N dopant into an empty surface state, e.g., a surface carbon radical. In addition, strong surface stabilization is observed for N substitution in certain sites via a beta-scission reconstruction, with the formation of sp2 carbon. These observations correlate well with observed surface degradation and decrease in growth rate when a high concentration of nitrogen gas is introduced into the CVD growth process. The effect of co-adsorbed P, S and B onto the diamond surface has also been investigated for two reaction steps: CH3 adsorption and H abstraction. While P and B are observed to influence these reaction steps, the effect of S is rather limited.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2009. 56 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 594
Keyword
diamond, growth, chemical vapour deposition, nitrogen, phosphorus, boron, sulphur, density functional theory
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-9539 (URN)978-91-554-7396-9 (ISBN)
Public defence
2009-02-27, Häggsalen, Ångström Laboratory, Lägerhyddsvägen, 1, 751 21 Uppsala, 10:15
Opponent
Supervisors
Available from: 2009-02-06 Created: 2009-02-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Materials Chemistry
In the same journal
Diamond and related materials
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 465 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf