Abstract
In self-assembled quantum dots (SAD), the relation between the electric dipole moment arising from the electron-hole separation and the Stark shift takes different forms as a function of SAD shape and composition. This effect is attributed to the strain field distribution that strongly influences the rapidly varying confining potential for holes, and changes substantially with the dot morphology. In particular, truncated pyramidal or elongated lens-shaped SADs exhibit the normal linear dependence of the Stark shift on the electric dipole moment, thereby reflecting a 2D character in the electron-hole confinement. At the opposite, SADs with large aspect ratio between height and base, e.g., with pyramidal or hemispherical shapes, show significant deviations of the Stark shift from the normal linear dependence on the dipole moment. We point out that this absence of correlation between the Stark shift and electric dipole moment reflects a true 3D confinement in SADs.
Original language | English (US) |
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Pages (from-to) | 50-55 |
Number of pages | 6 |
Journal | Physica E: Low-Dimensional Systems and Nanostructures |
Volume | 17 |
Issue number | 1-4 |
DOIs | |
State | Published - Apr 2003 |
Event | Proceedings pf the International Conference on Superlattices - ICSNN 2002 - Touluse, France Duration: Jul 22 2002 → Jul 26 2002 |
Keywords
- Quantum dots
- Stark effect
- Strain distribution
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics