Application of Kramers–Krönig analysis to the photoreflectance spectra of heavily doped GaAs/SI-GaAs structures

The photoreflectance spectra for heavily doped p-type GaAs/SI-GaAs structures have been measured at room temperature for the energies in the vicinity of the GaAs band gap. The complex photoreflectance function is defined and determined by means of a Kramers–Krönig analysis from the measured photoreflectance spectra. The modulus of the complex photoreflectance function gives us the critical point energy whereas the phase of this function can be used for a topographical study of the homogeneity of the internal electric field in the structure.