Abstract
We investigate optical transitions in ultrathin (GaAs)n(AlAs)n superlattices using resonance Raman scattering. For n = 1, 2, we find that superlattice-induced or "quasidirect" transitions have an oscillator strength comparable to bulk-like direct transitions. Theory, on the other hand, predicts the quasidirect transitions to be orders of magnitude weaker. Our results suggest that the discrepancy is due to Γ-X mixing in the conduction band of the superlattices. For bulk-like transitions, we find that the thickness dependence of energy and wavefunction localization disagrees with predictions based on effective-mass theory.
Original language | English (US) |
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Pages (from-to) | 65-68 |
Number of pages | 4 |
Journal | Surface Science |
Volume | 228 |
Issue number | 1-3 |
DOIs | |
State | Published - Apr 1 1990 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry