ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Antiarrhythmic activity of 17.beta.-aminoestratrienes. Comparison of 3-ols and 3-acetates with the corresponding 3-(3-amino-2-hydroxypropyl) ethers (1986)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 29 (1986), S. 244-250 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00152a013
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Erratum: "Substrate orientation effects on dopant incorporation in InP grown by metalorganic chemical vapor deposition'' [J. Appl. Phys. 73, 4095 (1993)] (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 2562-2562 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358542
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Substitutional, interstitial, and neutral zinc incorporation into InP grown by atmospheric pressure metalorganic vapor phase epitaxy (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 3221-3227 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Substitutional zinc incorporates linearly into device quality InP at low Zn source flow rate grown by atmospheric pressure metalorganic vapor phase epitaxy (AP-MOVPE) at 625 °C, and saturates around 4×1018 cm−3 at high Zn source flow rate. Increase in the Zn source flow rate beyond saturation significantly enhances interstitial incorporation. The excess interstitial diffuses into the undoped region via an interstitial-substitutional diffusion mechanism and reveals itself as an enhanced diffusion. Previously we have proposed a surface adsorption-desorption-trapping model for substitutional Zn incorporation during AP-MOVPE, where the saturation level is determined by the surface incorporation sites for substitutional Zn. This model is applied to interstitial Zn incorporation at Zn source flow rate above the saturation level for substitutional Zn to explain the enhanced Zn diffusion. The analysis is further extended to the incorporation of neutral Zn in the presence of excess phosphorus vacancies, therefore, this model can be used for simultaneous incorporation of Zn of all three types during epitaxy as long as the incorporation processes are independent. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363263
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Concentration dependent Zn diffusion in InP during metalorganic vapor phase epitaxy (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 3001-3007 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Concentration dependent diffusion of Zn during metalorganic vapor phase epitaxy from a Zn-doped InP layer into the adjacent undoped InP buffer layer were studied systematically using secondary ion mass spectroscopy and carrier concentration profiling. Under the condition that the growth rate of the Zn-doped film is faster than the interdiffusion of Zn into the underlying undoped buffer layer, the diffusion problem can be treated as a one-dimensional diffusion couple between two semi-infinite media. Furthermore, Zn diffusion during the optimized growth condition for InP completely eliminates the thermal decomposition problem encountered in the sealed ampoule and open tube diffusions and also maintains all the intrinsic point defects at their thermodynamic equilibrium concentrations. With an optimal growth temperature at 625 °C and a maximum Zn flow below the incorporation limit for substitutional Zn to ensure that the dominant Zn are incorporated substitutionally, the diffusion profiles of Zn across the interface in this simple and clean system are simulated using a concentration dependent diffusivity. A third power concentration dependence of the effective diffusion coefficient has been confirmed, which applies to both Frank–Turnbull and kickout interstitial-substitutional equilibrium mechanisms using an interstitial-substitutional diffusion model. This indicates a +2 charge state of the fast diffusing Zn interstitials. The extrapolated curve into high-concentration diffusion source regime used by sealed ampoule diffusion experiments generally agrees with the published results although the dominant Zn atoms found in the high-concentration diffusion source regime form complexes with phosphorous vacancies in a neutral state. The enhanced diffusion due to excess interstitials is discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360049
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Zinc incorporation into InP grown by atmospheric pressure metalorganic vapor phase epitaxy (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 1371-1377 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Zinc incorporation into InP grown by atmospheric pressure metalorganic vapor phase epitaxy has been studied systematically as a function of Zn source flow rate, substrate orientation, and growth temperature. Within the growth conditions for device quality layers, a Zn saturation level exists which varies with substrate orientation. The incorporation kinetics is analyzed using a surface adsorption-trapping model. We demonstrate that the Langmuir state of adsorption–desorption process is not established during growth due to the interruption of the surface processes by layer growth. The existence of a saturation level at a given growth condition indicates that Zn atoms incorporate at defect sites instead of the normal growth sites for In. Two parameters are used to characterize the properties of the surface defect, i.e., the capture cross section and the time of desorption for Zn atoms. The implication of these parameters and their substrate orientation and growth temperature dependencies are discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361035
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Misfit stress-induced compositional instability in hetero-epitaxial compound semiconductor structures (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 1397-1404 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have calculated the effect of misfit stress on the compositional stability of strained-layer hetero-epitaxial compound semiconductor structures. For uniformly stressed layers, a simple formula is derived for the change in chemical potential of the lattice atoms diffusing across the hetero-interface. An increase in the total chemical potential indicates that interdiffusion of the specific elements is thermodynamically unfavorable and therefore the composition of the structure is stable with respect to the misfit stress-induced interdiffusion of the specific elements. On the other hand, a decrease in the total chemical potential indicates that the interdiffusion will be driven by the misfit stress and the composition of the heterostructure is unstable. Various strain-layer systems of III–V compound semiconductors such as In1−xGaxAsyP1−y/InP, In1−xGaxAsyP1−y/GaAs, (Al1−xGax)yIn1−yP/GaAs, (Al1−xGax)yIn1−yAs/GaAs, In1−xGaxP/GaAs, In1−xGaxSb/InP, etc., are examined and their stability is discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361039
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Characteristics of GaAs/AlGaAs heterostructures grown by liquid-phase epitaxy on molecular-beam-coated GaAs on Si (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 3201-3204 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Liquid-phase epitaxy has been used to grow four-layer GaAs/AlGaAs double heterostructures on Si substrates that had been precoated with GaAs by molecular-beam epitaxy and coating the remaining exposed parts of the Si wafer with SiO2. Direct growth of GaAs on Si by liquid-phase epitaxy is not feasible because of the dissolution of the Si substrate by the Ga melt. As with the other growth techniques, photoluminescence from the GaAs cap layer and electroluminescence from the 0.2-μm-thick GaAs active layer indicate the luminescence peaks are shifted to lower energy as a result of the tensile strain in the plane of the layers that is caused by the different thermal contraction of the GaAS and Si layers as the wafer is cooled from the growth temperature. Optically pumped stimulated emission is observed from the cap layer at 80 K. The efficiency of the electroluminescence from the active layer was low, indicating the p-n junction was displaced from the active layer due to the accidental excess doping resulting from a slight dissolution of the Si substrate in the Ga melt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.341536
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Influence of {111} regrowth sidewall interfaces on the performance of 1.54 μm InGaAsP/InP etched-mesa-buried-heterostructure lasers (1987)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 61 (1987), S. 2434-2437 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The quality of {111} sidewall interfaces formed during liquid phase epitaxial regrowth around an etched mesa in an etched-mesa-buried-heterostructure laser device has been studied using cross-sectional transmission electron microscopy, cross-sectional transmission cathodoluminescence, and energy dispersive x-ray analysis. The results are correlated with the optical performance and electrical characteristics of the device before the aging test. It is found that the interfacial lattice imperfection will affect the device performance only when the defects are nonradiative recombination centers or they constitute a leakage path for the current. The possible causes for a defective interface will be discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.337913
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Optical properties of AlxGa1−x As (1986)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 60 (1986), S. 754-767 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report pseudodielectric function 〈ε〉 data for AlxGa1−xAs alloys of target compositions x=0.00–0.80 in steps of 0.10 grown by liquid-phase epitaxy and measured by spectroellipsometry. Cleaning procedures that produce abrupt interfaces between the technologically relevant alloys x≤0.5 and the ambient are described. The 〈ε2〉 data are corrected near the fundamental direct absorption edge by a Kramers–Kronig analysis of the 〈ε1〉 data to circumvent a limitation of the rotating-analyzer ellipsometric technique. The results and the associated pseudooptical functions 〈n〉, 〈R〉, and 〈α〉 are listed in tabular form. Accurate values of the E0 and E1 threshold energies are determined from these spectra by Fourier methods. From these values, and from similar values for a GaAs-capped AlAs sample grown by organometallic chemical vapor deposition, the dependencies of the E0 and E1 interband critical point energies on nominal composition are obtained. Cubic polynomial representations of these dependences are determined to allow nominal Al fractions to be calculated analytically from optical threshold data. The systematic behavior of 〈ε1〉 at 1.5 eV and of the E2 peak in 〈ε2〉 near 5 eV show that scatter in these data is less than 1% of the peak values of the spectra for x≤0.5. For x≥0.6 the peak data appear to show systematic discrepancies indicating that chemical cleaning cannot completely remove surface overlayers on high-Al-content samples. Optical measurements for a sample with x=0.9 also reveal the oxidation of high-Al samples proceeds irregularly and not along a uniform spatial front. Interpolation procedures to obtain approximate representations of dielectric function spectra at compositions other than those measured are discussed, and suggestions for improving accuracy in future optical measurements on these and related materials are also given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.337426
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Stimulated emission spectra of AlxGa1−xAs near the direct-indirect gap crossover composition (1986)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 59 (1986), S. 780-786 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The stimulated emission spectra of photoexcited AlxGa1−xAs, 0.42≤x≤0.46 (near the direct-indirect gap crossover xc =0.435) were measured at low temperatures as a function of the illuminated stripe length and excitation intensity. Based on these data, the gain spectra and gain saturation behavior were obtained. The observed gain spectra are explained by calculating the radiative recombination of an electron-hole plasma of constant density with fair agreement between theory and experiment. It is found that above xc the gain spectrum is due to electrons in the indirect-gap minima (X) whose wave function is strongly admixed with the (Γ) minimum by alloy disorder. The saturation of the stimulated emission at higher excitation intensity and at larger stripe length could be explained qualitatively for the direct-gap samples by a model based on electron and hole relaxation within their respective Fermi seas. This model yields the stimulated emission shift towards lower energy with increased excitation intensity or stripe length. The behavior of the indirect-gap samples is different: both ends of the gain spectrum saturate. This behavior cannot be explained by the proposed model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.336598
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...