In x Al1−x As/InP: organometallic molecular beam epitaxial growth and optical properties

In_xAl_1−xAs samples are investigated using photoluminescence at 5 K. A shift of the bandedge emission energy between OM-MBE and OMCVD samples of the same composition suggests that an impurity level is dominating the photoluminescence in the OM-MBE samples. This interpretation is supported by photoreflectance measurements. The photoluminescence is shown to be a very powerful technique to investigate the quality of In_xAl_1−xAs/InP interfaces. The interface seems to improve when we decrease its growth-halt time. A valence band offset in the range of 350 to 400 meV is estimated for this type II interface using InP quantum wells for electrons.