Library

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
    Al–Ga interdiffusion, carbon acceptor diffusion, and hole reduction in carbon-doped Al0.4Ga0.6As/GaAs superlattices: The As4 pressure effect (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 2450-2460 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Al–Ga interdiffusion, carbon acceptor diffusion, and hole reduction were studied in carbon doped Al0.4Ga0.6As/GaAs superlattices (SL) annealed under different ambient As4 pressure conditions in the temperature range of 825 °C–960 °C. The SL were doped with carbon to an initial acceptor concentration of ∼2.9×1019 cm−3. Al–Ga interdiffusion was found to be most prominent under Ga-rich annealing ambient conditions, with interdiffusivity values, DAl–Ga, turned out to be about two orders of magnitude smaller than those predicted by the Fermi-level effect model. Under As-rich ambient conditions, the DAl–Ga values are in approximate agreement with those predicted by the Fermi-level effect model. The hole concentrations in the SL decreased significantly after annealing under As-rich and As-poor ambient conditions, while those after annealing in the Ga-rich ambient were almost totally intact. By analyzing the measured hole concentration profiles, it has been found that both carbon acceptor diffusion and reduction have occurred during annealing. Both the carbon acceptor diffusivity data and the carbon acceptor reduction coefficient data are characterized approximately by a dependence on As4 pressure values to the one-quarter power. These As4 pressure dependencies indicate that carbon diffuses via the interstitialcy or interstitial–substitutional mechanism, while hole reduction is governed by a carbon acceptor precipitation mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354682
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Photopumped room-temperature continuous operation of native-oxide-embedded AlyGa1−yAs-GaAs-InxGa1−xAs quantum-well-heterostructure lasers (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 797-801 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data are presented on the 300 K (and 77 K) continuous photopumped laser operation of AlyGa1−yAs-GaAs-InxGa1−xAs quantum-well heterostructures (QWHs) that have been oxidized (H2O vapor+N2, 425 °C) selectively along the high-band-gap heterolayers located on either side of a GaAs waveguide (WG) region with an InxGa1−xAs QW in its center. Transmission electron microscope images show that the oxide-embedded GaAs-InxGa1−xAs WG+QW active region remains unoxidized and thus is sandwiched between electrically insulating AlyGa1−yAs native oxide layers. The thresholds for photopumped 300 K continuous laser operation of the as-grown and oxide-embedded QWHs are approximately equal after differences in the Ar+-laser photopumping efficiencies are considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354868
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Si impurity-induced layer disordering of Alx Ga1−x -GaAs quantum-well heterostructures by As-free open-tube rapid thermal annealing (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 6199-6206 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data are presented describing Si impurity-induced layer disordering (IILD) and Al-Ga interdiffusion in AlxGa1−x As-GaAs quantum-well heterostructures (QWHs) using open-tube rapid thermal annealing (900–1000 °C) in a flowing N2/H2 ambient. The data show that Al-Ga interdiffusion is enhanced by n-type crystal doping and suppressed by p-type doping. By surrounding the active layers of the heterostructure with layers of opposite doping, we show that the surrounding layers modify the interdiffusion by controlling the diffusion of point defects to the active layers of the heterostructure. Data are presented showing the effects of dielectric encapsulation (SiO2, Si3N4 ) on Al-Ga interdiffusion. The data show that regardless of doping SiO2 enhances interdiffusion as compared to Si3N4. To achieve more thorough layer intermixing of AlxGa1−x As-GaAs QWHs, Si IILD is also investigated in the high-temperature As-poor regime. The experimental data show that in a high-temperature As-poor annealing ambient, little or no Si diffusion occurs from an elemental Si source in contact with a p-type GaAs QWH cap layer. To achieve Si diffusion under these conditions requires removal of the GaAs cap and the use of Al-reduced SiO2 or Si3N4 as a Si diffusion source. Based on secondary-ion mass spectroscopic measurements, direct comparison of Si diffusion from closed-tube (825 °C, 48 h) and open tube (1000 °C, 10 min) anneals shows increased Si incorporation and layer disordering at higher temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346911
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Layer intermixing in heavily carbon-doped AlGaAs/GaAs superlattices (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 5615-5620 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Interdiffusion of Al and Ga in heavily C-doped Al0.3Ga0.7As/GaAs superlattice (SL) structures has been investigated quantitatively for a variety of ambient and surface encapsulation conditions. High-resolution photoluminescence (PL) at T=1.7 K was employed to evaluate the extent of layer intermixing after 24-h anneals at 825 °C. From the shifts to higher energies of the PL peaks due to n=1 electron-to-heavy hole transitions in the quantum wells of the annealed SLs relative to the position of this peak in the as-grown crystal, approximate Al-Ga interdiffusion coefficients (DAl-Ga) have been determined for different annealing conditions. For all encapsulants studied the interdiffusion in C-doped crystals is accelerated with increasing As4 pressure in the annealing ampoule. This result disagrees with previously observed trends for Group II-doped p-type structures, which have led to the charged point-defect model (Fermi-level effect) of Al-Ga interdiffusion. The Si3N4 cap has provided the most effective surface sealing against ambient-stimulated layer interdiffusion, and yielded DAl-Ga≈1.5−3.9×10−19 cm2/s. The most extensive layer intermixing has occurred for uncapped SL annealed under As-rich ambient (DAl-Ga≈3.3×10−18 cm2/s). These values are up to ∼40 times greater than those previously reported for nominally undoped AlxGa1−xAs/GaAs SLs, implying that the CAs doping slightly enhances host-atom self-diffusion on the Group III sublattice, but significantly less than predicted by the Fermi-level effect. The discrepancies between the experimental observations and the model, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346973
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Hydrogenation of Si- and Be-doped InGaP (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 5866-5870 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data are presented on the hydrogenation of Be-doped (p-type) and Si-doped (n-type) In1−xGaxP epitaxial layers grown lattice matched to GaAs (x ∼ 0.5). Low-temperature (1.7 K) photoluminescence, electrochemical carrier concentration profiling, and scanning electron microscopy are used to study the effects of hydrogenation on carrier recombination, carrier concentration, and surface morphology. Hydrogenation is found to passivate Si donors and Be acceptors and to improve photoluminescence efficiency, but causes mild surface damage. The carrier concentration following hydrogenation is found to be lowest in acceptor-doped material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346961
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Planar native-oxide buried-mesa AlxGa1−xAs-In0.5(AlyGa1−y)0.5P- In0.5(AlzGa1−z)0.5P visible-spectrum laser diodes (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 2521-2525 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data are presented demonstrating the continuous (cw) room-temperature (23 °C) operation of planar index-guided "buried-mesa'' AlxGa1−xAs-In0.5(AlyGa1−y)0.5P- In0.5Ga0.5P heterostructure visible-spectrum laser diodes. The planar "mesa'' structure is formed by "wet'' oxidation (H2O vapor+N2 carrier gas, 550 °C) of the AlxGa1−xAs on the composite AlxGa1−xAs-In0.5(AlyGa1−y)0.5P upper confining layer (outside of the active stripes). The oxidation process results in a ∼0.5-μm-thick native oxide located (in depth) within ∼3000 A(ring) of the active layer in the region outside of the laser stripes themselves. The oxide possesses excellent current-confinement properties and a low refractive index (n≈1.60), resulting in relatively low-threshold laser operation for narrow-stripe devices. In addition, these devices exhibit transverse-mode confinement and small beam astigmatism because of the refractive index step provided by the deep native oxide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351067
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Environmental degradation of AlxGa1−xAs-GaAs quantum-well heterostructures (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 2235-2238 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data describing the deterioration of AlxGa1−xAs-GaAs heterostructures in long-term exposure (2–12 years) to normal room environmental conditions (∼20–25 °C, varying humidity) are presented. Optical microscopy, scanning electron microscopy, transmission electron microscopy, and electron dispersion x-ray spectroscopy are used to examine AlxGa1−xAs-GaAs quantum-well heterostructure material that has hydrolyzed at cleaved edges, cracks, and fissures, and at pinholes in cap layers. The hydrolysis is found to be significant for thicker (〉0.1 μm) AlxGa1−xAs layers of higher composition (x〉0.85).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346527
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Hydrogenation-defined stripe-geometry In0.5(AlxGa1−x)0.5P quantum-well lasers (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 5871-5873 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data are presented on the continuous-wave (cw), room-temperature (300 K) operation of stripe-geometry In0.5(AlxGa1−x)0.5P quantum-well heterostructure lasers defined via hydrogenation. Passivation of the Zn acceptors in the cap and upper confining layer provides gain guiding, and elimination of the current-blocking oxide reduces the thermal impedance. The resultant device is capable of better performance than conventional oxide-stripe diodes fabricated on the same material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346962
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effect of annealing temperature on the hole concentration and lattice relaxation of carbon-doped GaAs and AlxGa1−xAs (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 5318-5324 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of the hole density in carbon-doped GaAs and AlxGa1−xAs as a function of the annealing temperature are presented. It is shown that after sample annealing at low temperatures (T〈550 °C), the hole concentration increases in all samples doped ≥1×1019 cm−3 with a simultaneous decrease in the hole mobility. However, sample annealing at higher temperatures (T(approximately-greater-than)600 °C) results in a reduction of the hole concentration in all samples doped with carbon at concentrations higher than ≈5×1019 cm−3. The reduction in hole concentration is also accompanied by an increase in lattice parameter of the carbon-doped epilayer. The observed changes in the electrical and microstructural properties are explained in terms of two different mechanisms: (1) the passivation of carbon acceptors by the incorporation of hydrogen during growth, and (2) the change in the lattice site location of carbon atoms upon annealing. Direct determination of the lattice site location of carbon in samples doped ≥5×1019 cm−3 showed that the fraction of interstitial carbon after annealing at T(approximately-greater-than)600 °C is at least 70% higher than in the as-grown samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352017
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Bistability and switching in a native-oxide-defined AlxGa1−xAs-GaAs quantum-well-heterostructure laser coupled to a linear array (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 5514-5516 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Bistability and switching are observed in the light versus current (L-I) characteristic of a native-oxide-defined AlxGa1−xAs-GaAs quantum-well-heterostructure stripe laser side-coupled to a linear array of end-coupled rectangular minilasers. These diodes, with internally coupled elements and the current partitioned among the elements, exhibit a large hysteresis in the L-I curve, with switching from the stimulated to the spontaneous regime occurring over substantial power (light) and current ranges. The linear array of minilasers and their resonances modulates and switches the stripe laser operation. The overall planar twin-stripe laser structure is defined by H2O vapor oxidation (425 °C), in patterned form, of a significant thickness of the high-gap AlxGa1−xAs upper confining layer of an AlxGa1−xAs-GaAs quantum-well heterostructure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351948
    Library Location Call Number Volume/Issue/Year 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...