Stability of large vacancy clusters in silicon

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Journal Title
Journal ISSN
Volume Title
School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2002
Major/Subject
Mcode
Degree programme
Language
en
Pages
115210/1-11
Series
Physical Review B, Volume 65, Issue 11
Abstract
Using a density-functional-based tight-binding method we investigate the stability of various vacancy clusters up to a size of 17 vacancies. Additionally, we compute the positron lifetimes for the most stable structures to compare them to experimental data. A simple bond-counting model is extended to take into account the formation of new bonds. This yields a very good agreement with the explicitly calculated formation energies of the relaxed structures for V6 to V14. The structures, where the vacancies form closed rings, such as V6 and V10, are especially stable against dissociation. For these structures, the calculated dissociation energies are in agreement with experimentally determined annealing temperatures and the calculated positron lifetimes are consistent with measurements.
Description
Keywords
silicon, defects, density-functional theory, positron annihilation
Other note
Citation
Staab, T.E.M. & Sieck, A. & Haugk, M. & Puska, Martti J. & Frauenheim, Th. & Leipner, H.S. 2002. Stability of large vacancy clusters in silicon. Physical Review B. Volume 65, Issue 11. 115210/1-11. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.65.115210.