ELECTRONIC STRUCTURE OF INAS/GAAS/GAASSB QUANTUM DOTS
| Autoři | |
|---|---|
| Rok publikování | 2011 |
| Druh | Článek ve sborníku |
| Konference | 3rd International Conference on NANOCON |
| Fakulta / Pracoviště MU | |
| Citace | |
| Obor | Fyzika pevných látek a magnetismus |
| Klíčová slova | quantum dots; GaAs; InAs; GaAsSb |
| Popis | The electronic structure of InAs quantum dots (QD) self assembled on GaAs and covered with the GaAs(1-y) Sb(y) strain reducing layer displays several interesting features, depending on the geometry and the composition of the ternary material. The basic motivation is the possible lowering of the emission energy towards the prominent communication bands of 1.3 and 1.55 microns. Using the envelope function theory, we investigate the localization of electrons and holes. The most remarkable finding is the localization of holes outside InAs, close to the base of the dot, for larger value of the Sb content. Thus, typeII molecular-like states are formed as the results of the strain and piezoelectric fields. The parameters of the ternary layer play a crucial role in forming the properties of the QD structures; some of them cannot be easily obtained by X-ray techniques. For this reason, we explore the possibility of efficient characterization of the very thin ternary layers in the QD heterostructures using VIS-UV reflectance spectra, and compare the results with those obtained by using X-rays. |
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