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
Filter
  • Blackwell Publishing Ltd  (11)
  • American Institute of Physics (AIP)  (9)
  • Nature Publishing Group
  • 2000-2004  (20)
  • 1
    Electronic Resource
    Electronic Resource
    Optical properties of undoped and modulation-doped AlGaN/GaN single heterostructures grown by metalorganic chemical vapor deposition (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 1817-1822 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The optical properties of undoped and modulation-doped AlGaN/GaN single heterostructures (SHs) grown by metalorganic chemical vapor deposition are investigated at low temperature using photoluminescence measurements. The formation of a two-dimensional electron gas at the heterojunction is verified by temperature-dependent Hall mobility and 300 K capacitance-voltage measurements. Radiative recombination is observed between the electrons in two-dimensional quantum states at the heterointerface and the holes in the flat-band region or bound to residual acceptors both in undoped and modulation-doped AlGaN/GaN SHs. These peaks disappear when the top AlGaN layer is removed by reactive ion etching. In addition, the photoluminescence results under different laser excitation intensity and lattice temperature are also described for undoped and modulation-doped AlGaN/GaN SHs with various Al compositions and growth interrupt times. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1330767
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Wetting layer carrier dynamics in InAs/InP quantum dots (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 3052-3054 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electronic coupling between InAs/InP quantum dot (QD) array and its wetting layer (WL) is studied by continuous wave and time resolved photoluminescence. The carrier dynamics is explained by the existence of two regimes in the WL: at low QD density the carrier dynamics is dominated by the diffusion and at high density when the distance between QDs is comparable to the carrier mean free path in the WL the quantum capture into QDs dominates. From the identification of these two regimes the carrier mean free path in the WL is estimated to about 30 nm. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1338953
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Direct measurement of the attenuation of capillary waves by laser interferometry: Noncontact determination of viscosity (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 2399-2401 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The determination of viscosity from the damping of capillary waves has been of great interest, as it affords the possibility of measuring viscosity without contact with the fluid. Here we describe a noncontact method for precision measurement of the amplitude of capillary waves on fluids. The technique utilizes a miniature laser interferometer to map the wave profile with a resolution of about 10 nm. We use this technique to obtain the dispersion and attenuation of capillary waves on water as a test case. Furthermore, the attenuation data is used to obtain the viscosity of water as a function of temperature. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1365413
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Observation of long photoluminescence decay times for high-quality GaN grown by metalorganic chemical vapor deposition (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 2503-2505 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: GaN epitaxial layers with different crystalline quality grown on sapphire substrates by metalorganic chemical vapor deposition are investigated using time-resolved photoluminescence at 300 K. It is found that the time-dependent photoluminescence of low-quality GaN decays faster than that of the high-quality GaN films. The time constants for the dual-exponential decay of the photoluminescence are calculated to be 50 and 250 ps for high-quality undoped GaN and 30 ps for low-quality undoped GaN. For high-quality Si-doped GaN, time constants of 150 and 740 ps are extracted while corresponding time constants of 40 and 200 ps are measured for low-quality Si-doped GaN. We believe that the time constant of 740 ps measured for our high-quality Si-doped GaN is the longest ever reported for thin GaN/sapphire films. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1318396
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    High-speed 1.55 μm Fe-doped multiple-quantum-well saturable absorber on InP (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 4065-4067 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Excitonic saturable absorption on iron-doped InGaAs/InP multiple-quantum-well structures is studied by Fourier transform infrared spectroscopy and pump-probe measurement in the 1.55 μm wavelength range. The recovery time of the excitonic absorption bleaching is improved by iron doping and is found to vary from 7 ns on the undoped sample to 7 ps on the highest doped sample. The samples exhibit high optical switching with a differential optical transmission coefficient of more than 20% and a saturation fluence smaller than 47 μJ/cm2. Furthermore, we notice no degradation of the contrast ratio due to iron doping. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1381410
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Height dispersion control of InAs/InP quantum dots emitting at 1.55 μm (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 1751-1753 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A procedure of InAs/InP quantum dots elaboration emitting at 1.55 μm by gas source molecular beam epitaxy is described. It is based on a modification of the capping layer growth which is deposited in two steps, separated by a growth interruption under phosphorus flux. The main effect of this two step capping layer growth is to reduce the height of the biggest islands and thus to decrease the photoluminescence linewidth of the quantum dots emission line. Transmission electron microscopy and photoluminescence experiments show that quantum dots structure are still present after growth interruption under phosphorus flux and that the photoluminescence linewidth at 1.55 μm is reduced from 120 to 50 meV, thanks to this procedure. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1356449
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Back illuminated AlGaN solar-blind photodetectors (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 1900-1902 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the growth, fabrication, and characterization of AlxGa1−xN (0≤x≤0.60) heteroepitaxial back-illuminated solar-blind p-i-n photodiodes on (0001) sapphire substrates. The group III-nitride heteroepitaxial layers are grown by low-pressure metalorganic chemical vapor deposition on double polished sapphire substrates using various growth conditions. The back-illuminated devices exhibit very low dark current densities. Furthermore, they exhibit external quantum efficiencies up to 35% at the peak of the photoresponse (λ∼280 nm). Improvements were made to the growth technique in order to achieve crack-free Al0.4Ga0.6N active regions on a thick Al0.6Ga0.4N window layer and to obtain activated p-type Al0.4Ga0.6N layers. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1311821
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Selective regrowth of Al0.30Ga0.70N p–i–n photodiodes (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 2810-2812 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on the device performance of selective-area regrown Al0.30Ga0.70N p–i–n photodiodes. Tensile strain, induced by the lattice mismatch between AlxGa1−xN and GaN, leads to cracking above the critical thickness in layers with high aluminum concentration. Selective-area regrown devices with ≤70 μm diameters were fabricated without signs of cracking. These devices show low dark current densities with flat photoresponse and a forward turn-on current of ∼25 A/cm2 at 7 V. A quantum efficiency greater than 20% was achieved at zero bias with a peak wavelength of λ=315 nm. A differential resistance of R0=3.46×1014 Ω and a detectivity of D*=4.85×1013 cm Hz1/2 W−1 was demonstrated. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1322374
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    High-voltage mesa-structure GaN Schottky rectifiers processed by dry and wet etching (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 2918-2920 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have fabricated and investigated high-voltage GaN vertical Schottky-barrier rectifiers grown by metalorganic chemical vapor deposition. A mesageometry Schottky-barrier rectifier having a 5-μm-thick i region, and processed using reactive-ion etching, exhibited a reverse breakdown voltage of −450 V (at 10 mA/cm2) and an on-resistance of 23 mΩ cm2. For comparison, we have also applied wet chemical etching for the fabrication of mesageometry Schottky-barrier rectifiers. The 2-μm-thick i-region GaN mesa-Schottky rectifiers showed a breakdown voltage of −310 and −280 V for wet-etched and dry-etched devices, respectively, and an on-resistance of 8.2 and 6.4 mΩ cm2, respectively. These results indicate that the performance of the wet-etched rectifiers is comparable to or better than that of comparable dry-etched devices. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1322050
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Mapping Coastal Aquifers by Joint Inversion of DC and TEM Soundings-Three Case Histories (2001)
    Oxford, UK : Blackwell Publishing Ltd
    Ground water 39 (2001), S. 0 
    Details
    ISSN: 1745-6584
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Notes: Electrical and electromagnetic methods are well suited for coastal aquifer studies because of the large contrast in resistivity between fresh water-bearing and salt water-bearing formations. Interpretation models for these aquifers typically contain four layers: a highly resistive unsaturated zone; a surficial fresh water aquifer of intermediate resistivity; an underlying conductive, salt water saturated aquifer; and resistive substratum. Additional layers may be added to allow for variations in lithology within the fresh water and salt water layers. Two methods are evaluated: direct current resistivity and time domain electromagnetic soundings. Use of each method alone produces nonunique solutions for resistivities and/or thicknesses of the different layers. We show that joint inversion of vertical electric and time domain electromagnetic soundings produces a more tightly constrained interpretation model at three test sites than is produced by inversion methods applied to each data set independently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1745-6584.2001.tb00354.x
    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...