Identification of defects at the interface between 3C-SiC quantum dots and a SiO2 embedding matrix

Márton Vörös, Adam Gali, Efthimios Kaxiras, Thomas Frauenheim, Jan M. Knaup

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Due to the favorable band offsets, SiC nanoparticles embedded in silica form a very interesting quantum dot (QD) system. It is possible to produce such QDs in a simple oxidation-carbonization-reoxidation process on Si wafers. This could thus enable production of Si based LED integrated into Si logic devices. However, the luminescence of these QDs, is quenched. This is attributed to defect-mediated recombination of electron-hole pairs, most probably at the SiC/SiO2 interface. We present tight-binding simulated annealing calculations, in order to construct models of SiC QDs in SiO2, with the aim of obtaining an overview of the possible defects at the SiC/SiO2 interface. We identify a number of recurring interface defects which can be attributed to C or Si rich conditions or general lattice mismatch relaxation. Similar to defects have been shown to be electrically active at the SiC/SiO2 interface in MOS structures. We find evidence for strained Si-Si bonds, which can act as recombination centers in isolated SiC QDs. The defect classes identified in this work can serve as the basis for future, high precision simulations of their electronic structure.

Original languageEnglish
Pages (from-to)360-367
Number of pages8
JournalPhysica Status Solidi (B) Basic Research
Volume249
Issue number2
DOIs
Publication statusPublished - Feb 2012

Keywords

  • DFTB
  • Defects
  • Interfaces
  • Quantum dots
  • SiC

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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