INTERFACE AND SURFACE SUBSIGNALS IN PHOTOREFLECTANCE SPECTRA FOR GAASSI-GAAS STRUCTURES/

Photoreflectance spectra were measured at room temperature for energie s in the vicinity of the E(0) critical point for p-type as well as n-t ype doped GaAs/SI-GaAs structures. Depending on the doping concentrati on the existence of two photoreflectance subsignals was observed; the first one arises from the surface space charge region while the second one from the interface region. The decomposition of photoreflectance spectrum into surface and interface subsignals was based on the photor eflectance measurements carried out for different wavelengths of the l aser pump beam.