Abstract
The application of two-photon absorption spectroscopy allows us to observe exciton states associated with high-index light-hole subbands in As/AlAs ternary-alloy quantum wells, which cannot be resolved in linear optical spectroscopy due to alloy broadening. The 2p-1s splitting energy of heavy-hole excitons up to the i=4 subband is determined to be 10 meV. Based on the observed energy separation between 2p light- and heavy-hole excitons with Δi=0 we derive a valence-band offset of Δ=340±15 meV for the x=0.37 ternary-alloy quantum wells. In addition, we provide experimental determination of the two-photon absorption coefficient in quantum wells.
- Received 9 April 1990
DOI:https://doi.org/10.1103/PhysRevB.41.12937
©1990 American Physical Society