Interband optical transitions in GaAs modulation-doped quantum wells: photoreflectance experiment and self-consistent calculations
Abstract
Photoreflectance spectra of AlGaAs/GaAs/AlGaAs wide quantum wells doped by Si up to Nd = 2 x 1018cm-3 were investigated at room temperature. Three kinds of spectral peculiarities were observed in photoreflectance spectra: a spectral line due to the GaAs band gap (1.42 eV), short-period Frantz-Keldysh oscillations originating from the barrier band gap (1.71 eV) and lines of subbands in the quantum well. The energies of optical transitions are determined by means of the least-squares approximation of experimental data by the sum of Aspnes relations. The experimental results are in good agreement with the self-consistent subband structure calculation. It is shown that with an increase of the doping level the energies of the interband transitions in the quantum well are changed.
- Publication:
-
Semiconductor Science Technology
- Pub Date:
- April 2006
- DOI:
- 10.1088/0268-1242/21/4/008
- Bibcode:
- 2006SeScT..21..462A