Resonant Raman scattering is investigated on GaInAs/AlInAs multiple quantum well (MQW) heterostructures, lattice-matched to InP substrates. The resonance is realized at several fixed laser lines by varying the hydrostatic pressure to tune the interband transition energies (in the neighborhood of the AlInAs band gap) into resonance. Our tight-binding calculation of the electronic envelope functions shows that the resonance is related to the optical transitions between electron and hole extended states. The strong resonant enhancement of Raman peaks occurs only for AlInAs LO phonons which are confined in the barrier layers, but not for GaInAs LO phonons, providing direct experimental evidence for the spatial distribution of extended excitons.
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering