[en] Free-carrier absorption due to chemical disorder as well as to introduced intentionally periodic fluctuations of composition, is calculated in mixed semiconductors with the zinc blende structure and dispersion relation that is typical for III-V and II-VI compounds. It is found that for low electron concentration, absorption coefficients due to chemical disorder and to ionized impurities are of the same order. Intentionally introduced periodic fluctuations of molar composition give an additional contribution to the absorption. This contribution for narrow period of the fluctuation (approximately 100 A) has the form of a well defined peak. (author)

[en] The influence of chemical disorder on the magneto-optical properties of mixed semiconductors with zincblende structure and dispersion relations typical of III-V and II-VI compounds is considered theoretically. The magneto-optical transitions between Landau levels are described, treating the potential due to the chemical disorder as a perturbation. It is found that all transitions between any two Landau levels are allowed (Δn >= 2). The absorption coefficient is non-vanishing for any polarization and frequency due to the presence of chemical disorder. For parallel and perpendicular light polarization additional Kohn or logarithmic-like divergencies of the absorption coefficient are obtained at phonon energies equal to (h/2π)ω = E/sub n//sup +-/ - E₀⁺. (author)

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[en] Deep hole traps in Be doped p-type Al_0.2Ga_0.8As grown by molecular beam epitaxy have been studied by the deep-level transient-spectroscopy method applied to samples with a Schottky diode configuration. Six hole traps, labeled as H1-H6, were found. Activation energies and capture cross sections have been determined for all the traps. Hole emission from the traps H1 and H2 was electric field dependent obeying the Poole-Frenkel effect relation. Their thermal activation energies when extrapolated to zero electric field were E_T1,0=0.31 and E_T2,0=0.36. For the traps H3-H6 the activation energies for emission were equal to: E_T3=0.30 eV, E_T4=0.46 eV, E_T5=0.55 eV and E_T6=0.59 eV. Comparison with the data for LPE material indicates that the levels H5 and H6 can be Cu and Fe related, respectively

[en] In the present paper the deep-level transient spectroscopy (DLTS) method was applied to investigate defects in Be-doped Al_0.5Ga_0.5As created during He⁺⁺-ion bombardment. The samples were irradiated at room temperature with two fluences of 0.3 MeV He⁺⁺ ions: 10¹¹ cm^-2 and 10¹² cm^-2. The studied samples had a net acceptor concentration equal to 10¹⁶ cm^-3. It was found that irradiation increases the concentration of three traps and produces at least two new traps. It was possible to determine the activation energy for one of them as being equal to 0.54 eV

[en] The investigation results of deep energy levels in epitaxial layers of GaAlAs (p-type) doped with beryl have been presented. Deep level transient spectroscopy (DLTS) measurements have been carried out in the temperature range 77 - 300 K. The results shows the existence of four type of hole type traps. The activation energies and hole capture cross-sections have also been estimated. 5 refs, 3 figs

[en] The investigation results of deep energy levels in Cd_0.99Mn_0.01Te (n-type) doped with gallium have been presented. Deep level transient spectroscopy (DLTS) measurements have been carried out in temperature range 80-420 K. The results show five types of electron traps. The activation energy of trapping levels and electron trapping cross-sections have been determined for observed traps. 2 refs, 3 figs, 1 tab

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