Abstract
We report low-temperature (77 K) electroreflectance and photoreflectance measurements of the -like optical transitions on a series of Ge/Si heterostructures (superlattices and quantum wells). For single and double quantum wells of any thickness, as well as for thick-layer superlattices (period ∼100 Å) the spectra can be understood in terms of quantum-confined bulk-Ge states. For thin (∼10 Å) multiple quantum wells and superlattices, zone-folding effects dominate the spectra. Actual confinement of the electronic states is determined by measuring the Raman spectrum of each sample in and out of resonance with a given transition.
- Received 17 August 1993
DOI:https://doi.org/10.1103/PhysRevB.48.18024
©1993 American Physical Society