Photoluminescence of InGaAs/GaAsBi/InGaAs type-II quantum well grown by   gas source molecular beam epitaxy
  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. 
Wenwu Pan, Liang Zhu, Liyao Zhang, Yaoyao Li, Peng Wang, Xiaoyan Wu,   Fan Zhang, Jun Shao, Shumin Wang
cond-mat.mtrl-sci