MAGNETOOPTICS AND STRAIN EFFECTS IN GAINAS-ALINAS AND GAINAS-INP QUANTUM-WELLS

Transitions between the Landau levels of the lowest electron and hole sub-bands have been observed in the inter-band optical absorption of a modulation doped Ga.47In.53AsAl0.48In.52As superlattice and a Ga0.3In.7AsInP strained layer superlattice, in magnetic fields up to 16T. In the unstrained sample, the energies of transitions up to 250 meV above the GaInAs band gap were found to be well described by a parabolic model for the heavy hole band and the model of Bowers and Yafet for the conduction band. In contrast to previous work on undoped quantum wells, no Coulomb binding effects were observed in this lightly doped sample, and this is attributed to screening of the exciton. In the strained sample, the heavy hole sub-band was found to show highly non-parabolic structure, and this is believed to be due to the effects of biaxial strain on the valence band.