Excitons based on spatially separated electrons and holes in Ge/Si heterostructures with germanium quantum dots
| Autor: | S. I. Pokutnyi |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Band gap Exciton Quantum point contact General Physics and Astronomy Strained silicon Heterojunction 02 engineering and technology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 01 natural sciences Multiple exciton generation Quantum dot 0103 physical sciences 0210 nano-technology Biexciton |
| Zdroj: | Low Temperature Physics. 42:1151-1154 |
| ISSN: | 1090-6517 1063-777X |
| DOI: | 10.1063/1.4973506 |
| Popis: | There is a significant increase in the binding energy between the exciton's space-separated electrons and holes (the hole moves across the volume of the quantum dot, and the electron is localized on a spherical surface of the quantum dot-matrix interface) in a nanosystem containing germanium quantum dots grown in a silicon matrix, in comparison to the binding energy of an exciton in a silicon single crystal. It is established that in such a nanosystem, in the conduction band of the silicon matrix there first exists a band of electron-hole pairs which turns into a band of exciton states located in the band gap of the silicon matrix, as the radius of the quantum dot increases. It is shown that the light absorption mechanisms in such nanosystems are implemented by electron transitions between quantum-levels of the electron-hole pair, as well as electron transitions between the quantum-exciton levels. |
| Databáze: | OpenAIRE |
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