Polarization resolved photoluminescence in GaAs1−xBix/GaAs quantum wells

We have investigated polarization resolved photoluminescence (PL) of GaAs1−xBix/GaAs quantum wells (QWs) with different Bi concentrations in the dilute range (x<2%) using linearly polarized laser excitation under high magnetic fields up to 15 T at low temperatures (T<14 K). It was found that the spin polarization and excitonic g-factor of GaAs1−xBix/GaAs QWs increase with the increase of Bi concentration. Excitonic gex-factors of 4 and 10 were obtained at 15 T for as-grown GaAs1−xBix/GaAs QWs with 1.2% and 1.9% Bi concentration, respectively. These values evidence an important increase of electron and hole g-factors with the introduction of Bi in GaAs.