Photoreflectance investigations of oscillator strength and broadening of optical transitions for GaAsSb–GaInAs/GaAs bilayer quantum wells.

GaAsSb–GaInAs/GaAs bilayer quantum wells which consist of two adjacent layers of GaAsSb and GaInAs sandwiched between GaAs barriers have been investigated by photoreflectance (PR) spectroscopy. The oscillator strengths of optical transitions in such multiheterointerface structures have been determined from the experiment and compared with the results of envelope function calculations. Additionally, the broadening of the PR features has been analyzed and a correlation has been found with the character of the transitions: the broadening increases significantly when the type of the transition changes from direct to indirect. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]