Indirect exciton absorption and Raman scattering in GaAs-AlGaAs superlattices
| Autor: | AN Forshaw, P.E. Simmonds, Skolnick, D. M. Whittaker, GW Smith, Tracey Fisher, D. J. Mowbray, D. W. Peggs |
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| Rok vydání: | 1994 |
| Předmět: |
Materials science
Photoluminescence Condensed matter physics Phonon Superlattice Exciton Double heterostructure Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Molecular physics Condensed Matter::Materials Science symbols.namesake symbols General Materials Science Photoluminescence excitation Electrical and Electronic Engineering Raman spectroscopy Raman scattering |
| Zdroj: | Superlattices and Microstructures. 15:317 |
| ISSN: | 0749-6036 |
| DOI: | 10.1006/spmi.1994.1061 |
| Popis: | Longitudinal optic (LO) phonon assisted indirect exciton creation (XLO), hot carrier relaxation ((e-h)LO) and Raman scattering phenomena are reported in the optical spectra of GaAs-AlGaAs superlattices. Structures of the same dimensions both with and without double heterostructure confining barriers are studied. For the structures without confining barriers, continuum transitions are suppressed in photoluminescence excitation (PLE) spectra, and as a result the XLO, (e-h)LO and Raman peaks are observed. The XLO absorption peaks are identified from the observation of a clear threshold in PLE at ℏωLO (36.4 meV) above the heavy hole exciton peak. The intensity of XLO is a maximum at 6 meV above the threshold, probably due to dissociation into free carriers at the exciton binding energy (6meV) above ℏωLO. The influence of non-radiative processes on incoherent (PLE) and coherent (Raman) processes is compared. |
| Databáze: | OpenAIRE |
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