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
Band alignment switching and the interaction between neighbouring silicon nanocrystals embedded in a SiC matrix
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 91, 165429-165435 p.Article in journal (Refereed) Published
Abstract [en]

We present results from density functional theory of the electronic properties of silicon nanocrystals (Si NCs) embedded in a silicon carbide (SiC) matrix, considering different combinations of various NCs and host matrix sizes. We show that the NC and the host matrix form a type-II band alignment, with the states at the top of the valence band being in the Si NC and the states at the bottom of the conduction band in the host matrix. Moreover, this band alignment can be interchanged with introducing oxygen at the interface. We demonstrate that the charge densities of some valence band states can overlap with the charge densities of the neighbouring NCs. We also demonstrate that this leakage of states is significant when the distance between the neighbouring NCs is less than ~1.6 nm.

Place, publisher, year, edition, pages
2015. Vol. 91, 165429-165435 p.
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:uu:diva-248553DOI: 10.1103/PhysRevB.91.165429ISI: 000353460000007OAI: oai:DiVA.org:uu-248553DiVA: diva2:799874
Available from: 2015-03-31 Created: 2015-03-31 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Theory and Modelling of Functional Materials
Open this publication in new window or tab >>Theory and Modelling of Functional Materials
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The diverse field of material research has been steadily expanding with a great help from computational physics, especially in the investigation of the fundamental properties of materials. This has driven the computational physics to become one of the main branches of physics, allowing for density functional theory (DFT) to develop as one of the cornerstones of material research. Nowdays, DFT is the method of choice in a great variety of studies, from fundamental properties, to materials modelling and searching for new materials. In this thesis, DFT is employed for the study of a small part of this vast pool of applications. Specifically, the microscopic characteristics of Zn1-xCdxS alloys are studied by looking into the evolution of the local structure. In addition, the way to model the growth of graphene on Fe(110) surface is discussed. The structural stability of silicon nanocrystals with various shapes is analysed in detail, as well.

DFT is further used in studying different properties of semiconductor nanocrystals. The size evolution of the character of the band gap in silicon nanocrystals is investigated in terms of changes in the character of the states around the band gap. The influence of various surface impurities on the band gap, as well as on the electronic and optical properties of silicon nanocrystals is further studied. In addition, the future use of silicon nanocrystals in photovoltaic devices is examined by studying the band alignment and the charge densities of silicon nanocrystals embedded in a silicon carbide matrix. Furthermore, the electronic and optical properties of different semiconductor nanocrystals is also investigated. In the case of the CdSe/CdS and CdS/ZnS core-shell nanocrystals the influence of the nanocrystal size and different structural models on their properties is analysed. For silicon nanocrystal capped with organic ligands, the changes in the optical properties and lifetimes is thoroughly examined with changes in the type of organic ligand.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2015. 93 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1247
Keyword
nanocrystals, graphene, alloys, density functional theory, optical properties, electronic properties, core-shell structures, semiconductors
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-248513 (URN)978-91-554-9231-1 (ISBN)
Public defence
2015-05-27, Å10132 (Häggsalen), Ångström Laboratory, Lägerhydddsvägen 1, Uppsala, 13:30 (English)
Opponent
Supervisors
Available from: 2015-05-05 Created: 2015-03-30 Last updated: 2015-07-07

Open Access in DiVA

No full text

Other links

Publisher's full texthttp://journals.aps.org/prb/abstract/10.1103/PhysRevB.91.165429

Authority records BETA

Kocevski, VanchoEriksson, OlleRusz, Jan

Search in DiVA

By author/editor
Kocevski, VanchoEriksson, OlleRusz, Jan
By organisation
Materials Theory
In the same journal
Physical Review B. Condensed Matter and Materials Physics
Condensed Matter Physics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 775 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