Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 31: Poster I: Devices, Quantum Dots and Quantum Wires

HL 31.20: Poster

Dienstag, 23. März 2010, 18:30–20:30, Poster D1

Influence of SiO₂ matrices on electronic and optical properties of silicon nanocrystals — •Kaori Seino¹, Friedhelm Bechstedt¹, and Peter Kroll² — ¹nstitut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Jena, Germany — ²Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX, USA

In recent years, there has been considerable interest in nanostructured silicon since it is a promising material for quantum devices of next generations. Nanocrystals (NCs) have attracted much attention due to the effects of the quantum confinement. Effects due to the confinement of electrons and holes in a region of reduced dimensions promise to overcome the limitation of the indirect-gap semiconductor Si for optoelectronic applications.

We perform calculations of Si dots in SiO₂ matrices for various dot sizes by means of density functionary theory within the local-density approximation (DFT-LDA). Many theoretical results are available for isolated NCs, e.g. hydrogenated Si NCs or partially or fully oxidized Si NCs. On the other hand, theoretical studies for Si NCs embedded in SiO₂ are limited. In our approach amorphous SiO₂ is used as matrix region, which leads to first calculations of electronic and optical properties within a realistic model. We demonstrate the strong influence of SiO₂ matrix on the electronic and optical properties of nanocrystalline silicon.