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
    Photothermal luminescence spectroscopy of GaAs/AlxGa1−xAs quantum wells (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 4555-4559 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A novel luminescence technique named photothermal luminescence has been developed. For the photothermal luminescence spectroscopy, the emission signal is caused by electronic transitions via the absorption of photons, followed by thermal excitation via electron-phonon interactions, and is monitored as a function of the excitation photon energy, in which the excitation photon energy is less than that of the emission signal. This new technique has been applied to the study of electronic transitions in GaAs/AlxGa1−xAs quantum wells. In addition to the observation of the n=1 electron-heavy-hole 1s and 2s exciton recombinations, a previously unreported fine structure in the n=1 electron-heavy-hole 1s exciton spectrum has also been observed. By measuring the temperature dependence of the spectra on different quantum wells, we suggest that the fine structure is due to the formation of the standing waves of acoustic vibrations in GaAs/AlxGa1−xAs quantum wells. We emphasize that due to the underlying mechanism of the technique, the photothermal luminescence provides a powerful tool to investigate the processes of electron-phonon interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Electroreflectance study of a symmetrically coupled GaAs/Ga0.77Al0.23As double quantum well system (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 3808-3814 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electroreflectance spectroscopy has been used to study a GaAs/Ga0.77Al0.23As symmetrically coupled double quantum well system as a function of externally applied electric field. Both intra- and inter-well exciton transitions were detected. The energy shifts of the coupled quantum confined levels are in good agreement with a theoretical calculation. Details of the lineshape fit yield important information about the modulation mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349184
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Temperature dependence of the photoreflectance of a strained layer (001) In0.21Ga0.79As/GaAs single quantum well (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 7537-7542 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have measured the photoreflectance spectra of a strained layer (001) In0.21Ga0.79As/GaAs single quantum well as a function of temperature in the range 10 K〈T〈500 K. The details of the lineshape of the fundamental conduction to heavy-hole feature (11H) demonstrates its excitonic nature even up to 500 K. From the temperature dependence of the 11H linewidth we have obtained important information about the quality of the material and interface. The variation of the 11H energy gap with temperature agrees with that of bulk material. Comparison of the energies of 11H and higher lying transitions with an envelope function calculation yields a conduction band offset parameter Qc=0.65±0.07.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349706
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Surface photovoltage spectroscopy and normal-incidence reflectivity characterization of a 1.3 μm InGaAlAs/InP vertical-cavity surface-emitting laser structure (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 6203-6205 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated a 1.3 μm InGaAlAs/InP (001) vertical-cavity surface-emitting laser (VCSEL) structure using surface photovoltage spectroscopy (SPS) and normal-incidence reflectivity. The SPS measurements were performed as a function of angle of incidence relative to the normal (0°–55°) and temperature (300 K〈T〈420 K). The SPS spectra exhibit both the fundamental conduction to heavy-hole excitonic transition and cavity mode plus a rich interference pattern related to the mirror stack. The advantages of SPS in relation to other methods to study VCSELs, such as photoreflectance and photocurrent spectroscopy, are discussed. This experiment demonstrates the considerable potential of SPS for the characterization of these device structures. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1467396
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Polarized-photoreflectance characterization of an InGaP/InGaAsN/GaAs NpN double-heterojunction bipolar transistor structure (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 4565-4569 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have characterized an InGaP/InGaAsN/GaAs NpN double-heterojunction bipolar transistor structure using polarized photoreflectance (PR) spectroscopy. The ordering parameter of the InGaP is deduced from the polarization {[110] and [11¯0]} dependence of the PR signals from the emitter region. The ordering related piezoelectric field is also found to influence the electric field, as evaluated from observed Franz–Keldysh oscillations, in the InGaP emitter region. The field in the emitter region is found to be about 25 kV/cm smaller than the theoretical value that does not take into account the possible ordering induced screening effect, while the field in the collector region agrees well with the theoretical value. In addition, the InGaAsN band gap is also determined by analyzing the PR spectrum of the base region. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1405823
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Room temperature polarized photoreflectance characterization of GaAlAs/InGaAs/GaAs high electron mobility transistor structures including the influence of strain relaxation (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 883-888 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using room temperature photoreflectance (PR) we have characterized the properties of three GaAlAs/InGaAs/GaAs high electron mobility transistor structures with two different well widths fabricated by molecular beam epitaxy on (001) GaAs substrates. The samples were denoted as #1, #2, and #3 with well widths of 140, 160, and 160 Å, respectively. Samples #2 and #3 were grown on substrates with different threading dislocation densities. For the latter two samples the well width exceeds the pseudomorphic limit so that there are some strain relaxation and related misfit dislocations as determined from the x-ray measurements. In order to detect the anisotropic strain of the misfit dislocations related to strain relaxation, the PR measurements were performed for incident light polarized along [110] and [11¯0] directions. Evidence for the influence of the strain relaxation upon the relaxed channel was provided by the observed anisotropy of the polarized PR signal in the InGaAs channel layer. Signals have been observed from every region of the sample, making it possible to evaluate the In and Al compositions, channel width and two-dimensional electron gas density, as well as the properties of the GaAs/GaAlAs multiple quantum well buffer layer. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.373751
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Piezoreflectance study of an Fe-containing silicon carbon nitride crystalline film (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 280-284 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A detailed piezoreflectance (PzR) study of an Fe-containing silicon carbon nitride crystalline film in the temperature range between 15 and 580 K was performed. From the line shape fit of the PzR spectra, the impurity to band and the direct band-to-band transition energies which are denoted as Ei and Egd, respectively, at various temperatures were accurately determined. The parameters that describe the temperature dependence of Ei and Egd are evaluated and discussed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371856
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Immunoblot Analysis of Exospore Polypeptides from Some Entomophilic Microsporidia (1986)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 33 (1986), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . Immunological relationships between genera and species of microsporidia were examined by immunoblot analysis. Exospore polypeptides from two Nosema spp., three Vairimorpha spp., and two undescribed Vairimorpha-like isolates were analyzed. Gel electrophoresis and immunoblot analysis revealed that a variety of polypeptides, mostly between 15,000 and 90,000 molecular weight, are present on the exospore. The three Vairimorpha spp. are closely related immunologically to each other, but less so to the two undescribed Vairimorpha-like isolates. The two Nosema spp. are immunologically distant from each other and from the Vairimorpha spp. Indirect evidence, however, indicated that many internal spore polypeptides present in both genera are similar. Cross-reactivity between exospore polypeptides from entomophilic microsporidia and antisera to a mammalian microsporidium, Encephalitozoon cuniculi, was very limited. These results indicate that immunoblot analysis of exospore polypeptides may be employed to investigate the interrelatedness of microsporidian species, and that exospore polypeptides of some microsporidia are sufficiently diverse to be of immunodiagnostic value.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1986.tb05548.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Piezoreflectance and photoreflectance study of GaAs/AlGaAs digital alloy compositional graded structures (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 460-466 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied the piezoreflectance (PzR) spectra at 300 and 80 K related to the intersubband transitions from two different (001) GaAs/AlGaAs structures, an asymmetric triangular quantum well and a rectangular quantum well, fabricated by molecular beam epitaxy using the digital alloy compositional grading (DACG) method. A comparison of the relative intensity of heavy- and light-hole related features in the PzR spectra and those in the photoreflectance emphasizes the contribution of the strain dependence of the energies of the confined states which allows us to identify the features associated with the heavy- and light-hole valence bands unambiguously. Comparison of the observed intersubband transitions with the envelope function calculations provides a self-consistent verification that the DACG method generated the desired potential profiles. Furthermore, the temperature dependence of both the energy position and broadening parameter of the fundamental conduction to heavy-hole (11H) and light-hole (11L) excitonic features are investigated in the range of 20–300 K. The anomalous behavior of the temperature dependence of the linewidth of 11H(L) excitonic features of the samples are discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360852
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Room-temperature photoluminescence, contactless electroreflectance, and x-ray characterization of a double-side delta-doped GaAlAs/InGaAs high electron mobility transistor structure (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 1851-1853 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using room-temperature photoluminescence and contactless electroreflectance we have characterized a double-side delta-doped Ga0.8Al0.2As/In0.2Ga0.8As pseudomorphic high electron mobility transistor structure fabricated by metal-organic chemical vapor deposition. Signals have been observed from every region of the sample making it possible to evaluate In and Al compositions, channel width, and two-dimensional electron gas density as well as the properties of the GaAs/GaAlAs superlattice buffer layer. The optical determination of the In composition and channel width are in good agreement with an x-ray measurement. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123690
    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...