Electroreflectance study of effects of indium segregation in molecular-beam-epitaxy-grown InGaAs/GaAsTunneling microscopy and spectroscopy on cross sections of molecularbeamepitaxygrown (Al)GaAs multilayers J. Vac. Sci. Technol. B 9, 779 (1991); 10.1116/1.585510 dc and ac transport in molecularbeamepitaxygrown metal/ZnSe/GaAs heterojunction structures Summary Abstract: Molecularbeam epitaxial growth of (Al,Ga) As/GaAs heterostructures with interruption at interfaces InxGa l _ xAs/GaAs single heterostructures have been grown by molecular-beam epitaxy with different growing rates and In molar fractions. Indium composition, layer thickness, and residual strain have been measured mainly by Rutherford backscattering/ channeling spectrometry and the results on selected samples compared with the results of other techniques like Auger electron spectroscopy and single-and double-crystal x-ray diffraction.Cathodoluminescence, x-ray topography, transmission electron microscopy, and ion dechanneling have been employed to observe dislocations and to characterize their nature and density. While the onset of misfit dislocations has been found to agree with the predictions of the equilibrium theory, the strain release has been found to be much lower than predicted and the results are compared with the available metastability or nucleation models. Present results are in best agreement with nucleation models. Moreover, annealing experiments show that these heterostructures are at (or very dose to) thermodynamic equilibrium. 1975

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A Raman spectroscopy study on highly mismatched GaAs layers with thickness ranging from 15 nm to 6.6 μm and grown by metal-organic vapor-phase epitaxy on InP (001) substrates, is reported. Both LO and TO GaAs phonons have been observed in backscattering and Brewster geometries. In the thinnest samples large frequency red shifts with respect to the bulk are measured indicating large residual tensile strains. The Raman measurements agree with x-ray-diffraction measurements and confirm that layers thinner than 30 nm exhibit a 3D growth mechanism as suggested by transmission electron microscopy investigations.

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Measurements of the ordinary refractive index of GaSe single crystals at various temperatures between 300 K and 75 K in the 0.5-2.5-eV energy range, obtained through an interference technique, are reported. On the basis of these data the energy dispersion of the thermal coefficient of the refractive index has been deduced by using a very simple computational approach. The experimental results were discussed in the framework of a single oscillator model of the optical constants.