Modified fermi-level pinning of the (100) GaAs surface through InAs quantum dots in different stages of overgrowth
| Autor: | C. Walther, R. P. Blum, H. Niehus, A. Thamm, W. T. Masselink |
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| Rok vydání: | 2000 |
| Předmět: |
Surface (mathematics)
Physics Condensed matter physics Solid-state physics Band gap Fermi level Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Electronic Optical and Magnetic Materials Condensed Matter::Materials Science symbols.namesake Etching (microfabrication) Quantum dot Fermi level pinning Materials Chemistry symbols Polar Electrical and Electronic Engineering |
| Zdroj: | Journal of Electronic Materials. 29:504-509 |
| ISSN: | 1543-186X 0361-5235 |
| DOI: | 10.1007/s11664-000-0035-2 |
| Popis: | The presence of InAs quantum dots on a {100} GaAs surface results in a pronounced increase of the Fermi level pinning energy. Using room-temperature photo-reflectance measurements combined with atomic force microscopy, we find that the presence of the quantum dots results in the Fermi level being pinned approximately ∼250 meV deeper in the bandgap, an effect which is reversed by either removing or overgrowing the dots. Both overgrowth and complete etching of quantum dots results in the disappearance of the polar InAs facets; we explain the change in Fermi level in terms of such facets. We also discuss the phase delay for the InAs related feature of the photoreflectance experiment as a detrapping of photo-generated electron-hole pairs in the dots. |
| Databáze: | OpenAIRE |
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