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Spin-polarized excitons in pseudomorphic, strained In(0.16)Ga(0.84)As/Al(0.29)Ga(0.71)As quantum wells on a GaAs substrate

Spin-polarisierte Exzitonen in pseudomorphen In(0.16)Ga(0.84)As/Al(0.29)Ga(0.71)As Quantentrögen auf GaAs Substrat
: Kunzer, M.; Hendorfer, G.; Kaufmann, U.; Köhler, K.


Physical Review. B 45 (1992), No.19, pp.11151-11155
ISSN: 0163-1829
ISSN: 1098-0121
ISSN: 0556-2805
Journal Article
Fraunhofer IAF ()
Anregungsspektroskopie; band offset; Banddiskontinuität; excitation spectroscopy; exciton; Exziton; optical pumping; optisches Pumpen; strained quantum well; verspannte Quantum Well

Circularly polarized excitation light from a tunable Ti-doped sapphire laser has been used to produce spin-polarized excitons in strained, pseudomorphic Insub0.16Gasub0.84As/Alsub0.29Gasub0.71As quantum wells (QW's) grown on GaAs substrates. By analyzing the degree of circular polarization of the exciton luminescence and by studying the depolarization effect of a transverse magnetic field, the optical lifetime and the spinrelaxation time of excited carriers can be determined in relatively wide wells. We further show that circular excitation offers a relatively simple means to discriminate unambiguously between light- and heavy-hole excitons. We have thus made measurements that yield optically determined band offsets for the QW system under investigation.