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
    Deep electron traps in GaAs/n-AlxGa1−xAs single-quantum wells (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 2408-2414 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Deep-level-transient spectroscopy on molecular-beam epitaxially grown square GaAs/ n-AlxGa1−x As (x=0.24–0.39) single-quantum wells shows a series of electron traps in the AlGaAs with energies EC−ET at 0.12, 0.22, 0.29, 0.52, and 0.63 eV and with concentrations of about 5×1015 cm−3. The defects are located in the upper AlGaAs layer near the GaAs well layer. The trap concentrations and the widths of the spatial trap distributions (typically 15 nm) are independent of the well width. For all traps, a nonexponential capture process which is logarithmic in time is observed. Time-dependent depth profiling shows a virtual shift of the trap distribution to the surface for shorter filling pulses. Both effects are due to the nonabrupt depletion edge (Debye tail). No direct emission from the quantum wells is observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.341674
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Incorporation and optical properties of magnesium in cubic GaN epilayers grown by molecular beam epitaxy (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 1835-1837 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The incorporation and optical properties of Mg in cubic GaN (c-GaN) epilayers grown by rf plasma-assisted molecular beam epitaxy on (100) GaAs are investigated by secondary ion mass spectroscopy and low-temperature photoluminescence (PL). By varying the Mg flux by more than four orders of magnitude, the incorporation of Mg saturates at high Mg flux and is limited to a value of about 5×1018 cm−3 due to the high volatility of Mg at growth temperature. In addition, we observe an accumulation of Mg at the GaN/GaAs interface due to a diffusion of Mg to the GaAs substrate. Low-temperature PL spectra reveal several well-separated lines. Besides a shallow acceptor level at EA≅0.230 eV, additional Mg-related deep defect levels indicate an incorporation of Mg at off-gallium sites or as complexes. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.122298
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    High resolution carrier temperature and lifetime topography of semi-insulating GaAs using spatially and spectrally resolved photoluminescence (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 1430-1434 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The temperature Te of photoexcited carriers in semi-insulating GaAs wafers is determined with high lateral resolution by topographic measurement of the spectrally selected band-to-band recombination luminescence intensity IPL. It is also calculated from a detailed balance between carrier excitation and recombination, taking into account optical phonon, electron-electron, piezoelectric, and acoustic phonon scattering processes. Comparison of the experimental and theoretical Te data yields the lifetime τ of the photoexcited carriers, which is thus obtained without time-resolved measurement. The lifetime results are corroborated by comparison of the measured and calculated dependence of Te on the laser excitation power. The relation between Te and τ for given excitation power allows for the generation of two-dimensional high-resolution lifetime topograms. The correlation with conventional IPL topograms is direct, duplicating the lateral cellular pattern with comparable fluctuation amplitude. From these properties, it is inferred that τ is dominantly determined by inhomogeneously distributed nonradiative recombination centers. Their concentration is low in the walls of the dislocation network and high in the interior of the cells. The statistical evaluation of Te topograms allows for an application-oriented comparison of the quality and homogeneity of GaAs wafers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353241
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Compositional analysis of molecular beam epitaxy grown InyGa1−yAs/GaAs/AlxGa1−xAs quantum wells by determination of film thickness (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3820-3826 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The thickness of the individual layers of molecular beam epitaxy grown pseudomorphic InyGa1−yAs (0.1≤y≤0.35)/GaAs/Al0.3Ga0.7As quantum well structures has been determined by transmission electron microscopy (TEM), secondary ion mass spectrometry (SIMS) depth profiling, and reflection high energy electron diffraction (RHEED) with the aim of the compositional analysis of the ternary alloy films. Agreement between SIMS and TEM thickness data within 15% is found. Reliable RHEED data at y≥0.25, where the number of RHEED oscillations is drastically reduced by the three-dimensional growth of the InGaAs film, have been obtained by averaging repeated RHEED measurements. As compared with TEM, RHEED tends to lower values by 10% at maximum. The compositional data determined by the different methods including also photoluminescence (PL) agree within 20% in the technologically important region y≥0.2. At y=0.1, extreme accuracy requirements concerning the thickness determination limit the accuracy of SIMS and TEM to around 30%. Therefore PL and RHEED are superior at this concentration. An influence of the growth temperature on the In content at y=0.3 could be detected only by PL, demonstrating the excellent relative accuracy of PL.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352889
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Intersubband transitions in partially interdiffused GaAs/AlGaAs multiple quantum-well structures (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 2195-2199 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Continuous tuning over the entire 8–12 μm wavelength range is demonstrated for the intersubband absorption resonance in n-doped GaAs/AlxGa1−xAs multiple quantum-well structures following partial interdiffusion of the well and barrier layers via rapid thermal annealing. The data indicate that redshifting of the intersubband absorption resonance arises both from interdiffusion-induced modification of the confining potential and from a decrease in the depolarization shift. The latter effect is due in part to a decrease in the free-carrier concentration within the Si-doped quantum wells following rapid thermal annealing. Significant diffusion of the localized Si dopant is also observed over the range of annealing temperatures investigated here. Calculated values of the Al-Ga interdiffusion coefficient, as a function of anneal temperature, indicate that Si diffusion through the heterointerfaces contributes substantially to layer intermixing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350334
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Structural and vibrational properties of molecular beam epitaxy grown cubic (Al, Ga)N/GaN heterostructures (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 2631-2634 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The radio-frequency plasma-assisted molecular beam epitaxy of cubic AlyGa1−yN/GaN heterostructures on GaAs(001) substrates is reported. Rutherford backscattering spectroscopy, high resolution x-ray diffraction, and first-order micro-Raman spectroscopy measurements were used to characterize the structural and vibrational properties of the alloy epilayers. The Al content of the alloy is in the range from 0.07〈x〈0.20. X-ray diffraction reciprocal space maps demonstrate the good crystal quality of the cubic (Al, Ga)N/GaN films. The measured Raman shift of the TO phonon mode of the AlyGa1−yN alloy is in good agreement with theoretical calculations. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1345858
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Optical constants of cubic GaN in the energy range of 1.5–3.7 eV (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 404-407 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The refractive index and extinction coefficient of cubic GaN in the energy range of 1.5–3.7 eV were determined with high accuracy using combined reflectivity and spectroscopic ellipsometry studies of layers grown by molecular beam epitaxy on GaAs(001). A comparison of the experimental reflectivity data with theoretical calculations demonstrates that the data analysis has to be performed by taking into account both surface roughness and a nonabrupt substrate–film interface. In the transparent region the refractive index of cubic GaN was found to be slightly higher than that of the hexagonal modification. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369398
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Cathodoluminescence analysis of cleaved facets of a ZnSe p–n junction (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 3823-3828 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: ZnSe diodes grown on (100) GaAs substrates by molecular beam epitaxy were investigated using cathodoluminesence (CL) measurements at sample temperatures between 50 and 300 K. The CL line scans at different photon energies were performed on cleaved p–n junctions at 50 and 300 K, respectively. Taking into account surface recombination, carrier generation volume, carrier diffusion and internal built-in electric field and related carrier drift, the CL measurements from cleaved p–n junctions could be qualitatively explained. The charge depletion layer has a strong influence on the CL measurements. The calculated charge depletion width is in good agreement with CL measurements. The experimental data from the spatially resolved CL on the cleaved ZnSe diodes revealed important information of the carrier dynamics and recombination processes in these devices. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.372420
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Laser-beam heating and high-temperature luminescence of CdTe (1987)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 62 (1987), S. 369-373 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: High-temperature luminescence excited by a cw Kr-ion laser beam was used as a probe to measure the temperature of CdTe inside of the laser spot. The luminescence was first studied with low-power laser excitation on externally oven-heated CdTe. The results were then used as a standard for the temperature determination during laser-beam heating. It was found that the lattice temperature can be determined very accurately from the slope on the high-energy side of the luminescence spectrum. The maximum temperature inside the laser spot was measured as a function of the laser power. The results are in good agreement with theoretical calculations of cw laser heating in CdTe.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.339806
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Photoluminescence from quantum dots in cubic GaN/InGaN/GaN double heterostructures (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 1243-1245 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have measured photoluminescence spectra of molecular-beam-epitaxy-grown cubic GaN/InxGa1−xN/GaN double heterostructures with x between 0.09 and 0.33. We observe a luminescence peak at about 2.3–2.4 eV which is almost independent of the InGaN layer composition. High-resolution x-ray diffraction measurements revealed a pseudomorphic In-rich phase with x=0.56±0.02 embedded in the InGaN layers. Including strain effects we calculate a gap energy Eg=2.13 eV of this phase. In cubic InGaN, spontaneous polarization and strain-induced piezoelectric fields are negligible. Therefore, the observed difference between the luminescence energy and the gap of the In-rich phase is assumed to be due to the localization of excitons at quantum-dot-like structures with a size of about 15 nm. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1396314
    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...