Interference effects in photoreflectance of epitaxial layers grown on semi-insulating substrates

摘要

Interferences were observed in the photoreflectance spectra of homoepitaxial layers grown on semi‐insulating GaAs and InP substrates. The modulation mechanism responsible for the interference effect was studied from the frequency and temperature dependence of the interference amplitude and the effect of continuous wave illumination. The results are in agreement with the model that the modulation is due to electrons drifting to the interface from the surface. A simple model was used to fit the interference spectra to the Lorentzian wave forms from the substrate and the epitaxial layer.