Optical study ofAl0.4Ga0.6Sb/GaSbsingle quantum wells

Abstract

Despite the recent upsurge in research on GaSb-based systems, only few systematic investigations have been performed on the fundamental optical and electronic properties of Al x Ga 1Ϫx Sb/GaSb quantum wells. For this reason we studied a series of Al 0.4 Ga 0.6 Sb/GaSb single quantum wells, with well thicknesses ranging from 40 to 117 Å, by reflectance ͑R͒ and photoreflectance ͑PR͒ in the 0.6 to 1.5 eV spectral range and at temperatures from 6 to 300 K. The structures were grown by molecular-beam epitaxy on ͑001͒ GaSb substrates and structurally and compositionally characterized by photoluminescence, x-ray diffraction, and reflection highenergy electron diffraction. Both R and PR spectra showed clear evidence of the structures associated with the transitions allowed between the nth heavy-͑light-͒ hole subband and the nth conduction subband for nϭ1 and 2. Standard critical-point line shapes fitted satisfactorily the PR structures, allowing accurate determination of both transition energies and broadening parameters as functions of the well thickness. The transition energies were well fitted by a theoretical model based on the envelope-function scheme, thus giving reliable values for the two fit parameters, i.e., the band offset and the conduction-band nonparabolicity. ͓S0163-1829͑99͒05423-5͔ PHYSICAL REVIEW B 15 JUNE 1999-I VOLUME 59, NUMBER 23 PRB 59 0163-1829/99/59͑23͒/15395͑7͒/$15.00 15 395

Characterization of GaSb/AlGaSb Multi-Quantum-Well Structures Grown on Si(001) Substrates

“…The material parameters used for this model are listed in the inset of this figure. 13,14) The experimental data indicated by solid circles are in good agreement with the relationship between emission energy and well width calculated using this simple model.…”

AlGaAsSb superlattice buffer layer for p-channel GaSb quantum well on GaAs substrate

“…2 shows room temperature (RT) PL spectra of the samples #3, 4, and 5 with different SL growth temperatures (530, 500, and 470 1C, respectively). All the QW spectra show primary peak corresponding to the ground state HH1-C1 recombination (heavy-hole subband #1-conduction subband #1) [7] and the shape of the spectra is very similar to the previously published [8].…”

Comparison of structural and optical properties of GaSb/AlGaSb quantum well structures grown on different oriented Si substrates

“…[11]. noteworthy that the PL peak energies of MQW on Si(111) are nearly constant up to $120 K. Although the origin of the weak temperature dependence of MQW on Si(111) and Si(0 11) substrates is not clear yet, it is likely that the experimental results are related to the difference in direction of strain in MQW layers.…”