Showing papers by "Harri Lipsanen published in 1993"
TL;DR: In this paper, a simple model was used to fit the interference spectra to the Lorentzian wave forms from the substrate and the epitaxial layer, and the results were in agreement with the model that the modulation is due to electrons drifting to the interface from the surface.
Abstract: 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.
29 citations
TL;DR: In this article, the photoluminescence spectra measured at 12 K show both exciton and donor-acceptor peaks, the magnitudes of which depend on the PrO2 doping.
Abstract: Praseodymium dioxide (PrO2) -doped In0.69Ga0.31As0.67P0.33 layers are grown on semi-insulating InP substrates with liquid-phase epitaxy. The PrO2 doping of the growth solution varies from 0 to 0.32 wt %. The quaternary In0.69Ga0.31As0.67P0.33 layer composition determined with two-crystal X-ray diffraction and photoreflectance is found to be independent of the PrO2 concentration in the melt. The photoluminescence spectra measured at 12 K show both exciton and donor-acceptor peaks, the magnitudes of which depend on the PrO2 doping. The carrier concentration of the n-type quaternary layer decreases and the mobility increases with increasing PrO2 concentration and reaches the values of 8.3•1015 cm-3 and 7300 cm2/Vs, respectively, at about 0.1 wt% at 77 K. The experiments show that PrO2 has an impurity gettering effect in the growth process.
2 citations