  InGaAs/GaAsBi/InGaAs quantum wells (QWs) were grown on GaAs substrates by gas
source molecular beam epitaxy for realizing the type II band-edge line-up. Both
type I and type II transitions were observed in the Bi containing W QWs and the
photoluminescence intensity was enhanced in the sample with a high Bi content,
which is mainly due to the improvement of carrier confinement. Blue-shift of
type II transitions at high excitation power density was observed and ascribed
to the band-bending effect. The calculated transition energies based on 8 band
k.p model fit well with the experiment results. The experimental and
theoretical results show that the type-II QW design is a new promising
candidate for realizing long wavelength GaAs-based light emitting devices near
1.3 um.
