Abstract
The excitonic properties of cubic ZnS quantum wells in ZnMgS are studied by reflectivity and magnetooptics. A remarkable improvement in the quality of the samples grown by molecular-beam epitaxy on GaP substrates has allowed the observation of heavy- and light-hole exciton transitions with values for the full width at half maximum as narrow as 5 meV. The 2s state of the heavy-hole exciton is identified and exciton binding energies of as high as 55 meV are deduced, indicating that for quantum wells narrower than 3.5 nm the exciton-LO phonon scattering can be suppressed. Zeeman splittings of the order of 10 meV for both the light and heavy-hole exciton transitions appear in magnetoreflectivity spectra in magnetic fields up to 54 T. Large light-hole exciton g values of the order of 4 for all quantum wells are obtained due to the light hole being the uppermost valence band in these tensile-strained quantum wells. A strong reduction in the diamagnetic shifts for narrow wells is observed due to increasing quantum confinement.
| Original language | English |
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| Article number | 155321 |
| Pages (from-to) | 1553211-1553216 |
| Number of pages | 6 |
| Journal | Physical Review B: Condensed Matter and Materials Physics |
| Volume | 64 |
| Issue number | 15 |
| Publication status | Published - 15 Oct 2001 |