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
    In-plane electrical transport in n-type selectively doped GaSb/AlGaSb multiquantum wells (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 5166-5170 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Results are reported regarding in-plane electrical transport in n-type selectively doped GaSb/AlGaSb multiquantum wells. In the samples, which were grown by molecular beam epitaxy, only the central regions of the Al0.40Ga0.60Sb barriers were Te doped. Low-field, low-temperature Hall measurements in the dark demonstrated the presence in the GaSb wells of a degenerate electron gas with nonzero occupancy only for the lowest miniband. A positive persistent photoconductivity effect, related to the DX character of the Te impurity, was also observed. This behavior enabled the μ electron mobility to be measured at T=10 K as a function of the nS sheet carrier density. Since the experimental data were consistent with a dominant role of the interface roughness scattering in the limiting of μ, the height, Δ, and the lateral size, Λ, of the interface roughness were determined from the analysis of the μ=μ(nS) dependence. Acceptable values of Δ were obtained, consistent with results of structural investigations in single quantum well samples of GaSb/Al0.40Ga0.60Sb [E. Kh. Mukhamedzhanov, C. Bocchi, S. Franchi, A. Baraldi, R. Magnanini, and L. Nasi, J. Appl. Phys. 87, 4234 (2000)]. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1407310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Occupancy level of the DX center in Te-doped AlxGa1−xSb (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 256-263 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hall effect measurements were performed in Te-doped AlxGa1−xSb layers grown by molecular beam epitaxy to investigate the composition dependence of the DX center occupancy level. The investigated samples have AlSb molar fractions in the 0.25≤x≤0.50 range and n-type doping of about 1018 cm−3. A family of x(approximate)0.40 samples of different doping (5×1015–1018 cm−3) were also studied. The Hall electron density data versus temperature were analyzed at high temperatures (T≥150 K) where the DX center is at equilibrium, by assuming the negative-U model for the DX level and by taking into account the multivalley conduction effects. The DX level, degenerate in energy with the conduction band at low x values, enters the forbidden gap at x(approximate)0.25 and then it becomes deeper with increasing x. In lightly doped samples, the introduction of a second level of the same Te impurity is required to fit the data; such level can be identified with the nonmetastable level which controls the low temperature electrical properties of the material. A critical discussion on the choice of the conduction band parameters for the fitting is reported. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369438
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Determination of the occupancy level of the DX center resonant with the conduction band in Te-doped AlGaSb (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 3015-3020 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The analysis of the amplitude of the deep level transient spectroscopy signal due to DX centers is exploited to determine the EDX occupancy level of the DX center in Te-doped AlxGa1−xSb in the range of low values of x where EDX is resonant with the conduction band. We take advantage of a small but still detectable change in the occupancy factor of the DX level induced by the filling pulse. It is shown that EDX is very close to the L conduction band edge for x≤0.20. This behavior is different from the one at x≥0.30 where EDX lies in the forbidden energy gap and exhibits an x dependence similar to the X edge. These results are discussed at the light of different atomic configuration for DX centers at an anion-substitutional impurity. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1445495
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Photoionization cross-section of the DX center in Te-doped AlxGa1−xSb (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 491-496 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The photoionization of DX centers in Te-doped AlxGa1−xSb layers grown by molecular beam epitaxy is investigated by measuring the increase of the Hall free electron density after illumination by monochromatic light in the temperature range typical of the persistent photoconductivity (PPC) effect. The investigated samples have AlSb molar fractions in the 0.3≤x≤0.5 range and n-type doping in the 1017−1018 cm−3 range. An accurate investigation of the isothermal photoionization transients is performed to evidence features in the curve not directly related to the phenomenology of the DX center, the free electron density being influenced by the possible occupancy of other impurity levels. The transients show, in particular, an initial nonexponential behavior which is demonstrated as due to localization of a fraction of the photoexcited electrons into a nonmetastable impurity state which is responsible for the semiconductor-to-metal transition observed under the PPC regime. When this effect is accounted for, the dependence of the photoionization cross section of the DX center on the photon energy was obtained from the analysis of the linear part of the transients and analyzed through a model given in the literature. The analysis gives values of the optical ionization energy and of the Frank-Condon shift varying in the ranges of 0.84–0.95 and 0.70–0.74 eV, respectively, depending on the alloy composition. This confirms a large lattice relaxation for the DX center related to the Te-impurity in AlxGa1−xSb. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.366720
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A wire-chamber spectrometer for muon spin rotation
    Amsterdam : Elsevier
    Nuclear Instruments and Methods In Physics Research 214 (1983), S. 509-516 
    Details
    ISSN: 0167-5087
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0167-5087(83)90624-5
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Study of the lattice strain relaxation in the Ga1-X Al X Sb/GaSb system by x-ray topography and high resolution diffraction (1999)
    Springer
    Journal of materials science 10 (1999), S. 185-190 
    Details
    ISSN: 1573-482X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract High resolution x-ray diffraction and topographic methods have been used to study lattice strain relaxation in the Ga1-X Al X Sb/GaSb system. Samples with layer thickness ranging between 0.1 and 6 μm and with Al concentration x=0.402±0.005 have been grown by molecular beam epitaxy at 550 °C on (0 0 1) oriented undoped GaSb LEC substrates. A first critical thickness (t C1), related to the misfit dislocation generation, has been found to be between 0.16 〈 t C1 〈 0.20 μm. Due to the weak sensitivity of the rocking curve to the onset of relaxation, this result has been obtained by means of a double crystal topographic technique. A “plateau” region in the curve of the residual strain versus thickness has been observed for t ranging between 0.2 and 0.5 μm. The residual strain ɛres shows a dependence close to t–0.5 above a second critical thickness value t C2 slightly larger than 0.5 μm. Finally, in the last region above a layer thickness of 3 μm, strong dislocation interaction effects seem to affect the relaxation. A comparison with theoretical models has been made.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008987710885
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Symmetry and non-symmetry for the overdetermined Stekloff eigenvalue problem (1994)
    Springer
    Zeitschrift für angewandte Mathematik und Physik 45 (1994), S. 44-52 
    Details
    ISSN: 1420-9039
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract We consider the Stekloff eigenvalue problem (1.1)–(1.2); Payne and Philippin conjectured that ifu is an eigenfunction which satisfies the overdetermined condition ▽u=1 on ∂Ω, then Ω should be a disk. In this paper we show that this conjecture holds if and only if the complex potentialF associated tou vanishes only at one point. Then we show how to construct non-symmetric domains in the case whereF vanishes at more than one point.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00942845
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The boundary integral method for two-dimensional orthotropic materials (1987)
    Springer
    Journal of elasticity 18 (1987), S. 61-82 
    Details
    ISSN: 1573-2681
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00155437
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Ueber die Untersuchung des Blutes (1902)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 41 (1902), S. 388-391 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01349555
    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...