Journal article
Dynamics of excitonic states in GaAs/AlGaAs quantum wells
The influence of photoexcited carriers on the dynamics of the absorption spectra of GaAs/AlxGa1−2x As multilayer quantum wells is investigated experimentally. It is found that at quasiparticle densities all the way up to 1011 cm−2 the saturation of the excitonic absorption is due to both a decrease of oscillator strength and broadening of the excitonic lines.
It is shown that in the case of femtosecond resonance laser exci-tation the decrease of oscillator strength is due to free electron-hole pairs, while the broadening and energy shift of the excitonic lines are due to the exciton-exciton interaction. The lifetimes of free electron-hole pairs and excitons (≈65 ps and ≈410 ps, respectively) are determined from the exponential decrease of the change in the oscillator strength and in the width and energy position of the excitonic lines.
Language: | English |
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Publisher: | Nauka/Interperiodica |
Year: | 1997 |
Pages: | 144-150 |
ISSN: | 10906487 and 00213640 |
Types: | Journal article |
DOI: | 10.1134/1.567493 |
ORCIDs: | Hvam, Jørn Märcher |