Abstract
We report highly resolved photoluminescence excitation spectra of excitons in intrinsic pseudomorphic As/GaAs quantum wells (QW’s). The QW parameters are chosen such that only the =1 electron and hole subbands are confined and the light-hole–heavy-hole exciton splitting exceeds the exciton binding energy. By using circularly polarized light the fine structure of excitonic transitions is well resolved in the spectra of quantum wells at magnetic fields H≤8 T. We observe a strong mixing of light- and heavy-hole excitons which causes optical transitions into high-angular-momentum exciton states and results in strong anticrossing effects. Two excited states of the exciton located at ≊1 and 2.5 meV above the 1s light-hole exciton state have been observed and are related to exciton states with the carrier-wave-function delocalized into the GaAs barriers.
- Received 28 March 1994
DOI:https://doi.org/10.1103/PhysRevB.50.7467
©1994 American Physical Society