Determination of energy difference and width of minibands in GaAs/AlGaAs superlattices by using Fourier transform photoreflectance and photoluminescence

In this work, Fourier transform photoreflectance (in a form of fast differential reflectance spectroscopy) has been used to study the interband optical transitions in molecular beam epitaxially grown GaAs/AlGaAs superlattices. The dependence of the measured features on the growth parameters (QW and barrier widths) has been studied. The minibands widths and energy differences between them have been obtained and matched to these coming from effective mass calculations. In addition, it has been shown that Fourier transform photoluminescence measurement might be used in the far infrared region (up to ∼15 μm) to the direct detection of the energies of intraband transitions between the electron minibands (subbands) in the superlattice and QW system.