Received 28 September 2015; revised 23 November 2015; accepted 15
December 2015
The ionizing radiation induced disordered
defect clusters and their relaxation in silicon were simulated
by the density functional method. It was found that a
non-relaxed disordered cluster gives rise to a great number of
localized states having their energy levels within the
semiconductor forbidden band gap. After the relaxation,
however, the density of these states significantly decreases
leaving only several relatively shallow donor and acceptor
state levels that may contribute to trapping of free carriers
and shrinkage of an effective band gap.
Keywords: radiation
clusters, disordered semiconductor, local levels
PACS: 61.72.J-,
29.40.Wk, 61.80.Az, 71.15.Mb
Jonizuojančioji spinduliuotė
sukuria netvarkias defektų sankaupas. Nedidelės sankaupos ir
sukurtos sankaupos modeliuotos tankio funkcionalo metodu silicio
kristale. Gauta, kad nerelaksavusios sankaupos sukuria daug
lokalizuotų būsenų draustinėje juostoje. Pasibaigus relaksacijai
didžioji dalis šių būsenų sumažėja ir lieka santykinai seklių
donorinės ir akceptorinės prigimties lygmenų, kurie gali daryti
įtaką krūvininkų prilipimui bei mažinti efektinį draustinės
juostos plotį.
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