ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Wiley  (84)
  • American Institute of Physics (AIP)  (20)
  • Molecular Diversity Preservation International  (20)
  • New Haven, CT: Yale University, Economic Growth Center
  • 11
    Digitale Medien
    Digitale Medien
    Thermal degradation effects in InP (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 63 (1988), S. 4677-4682 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Thermal degradation in InP has been regarded to be equivalent to surface deformation. By means of luminescence microscopy we discovered a much larger scale of degradation effects. Crystallographic defects of several geometrical characteristics have been observed although the surfaces seemed to be perfectly smooth. The standard methods of protection against degradation used in liquid phase epitaxy turned out to be unreliable concerning the invisible degradation effects. We propose a model which describes the evolution of degradation starting with invisible crystallographic defects. An extreme loss of phosphorus concentrated around dislocations causes local melting representing the final and visible stage of degradation. We suppose that P vacancies which have never been noticed before are responsible for inhomogeneities affecting processing and the reliability of optoelectronic devices.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.340122
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 12
    Digitale Medien
    Digitale Medien
    Bandwidth enhanced metal-semiconductor-metal photodetectors based on backgated ip structures (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 2223-2225 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report on theoretical and experimental results on a novel metal-semiconductor-metal (MSM) photodetector with a backgate provided by a p-doped layer. The backgate allows extremely short sweep-out times for the holes, due to strong electric fields normal to the surface. Thus, long tails due to slow moving holes and screening of the external drift fields by hole space charge accumulation at high optical power, which lead to a degradation of the time response of conventional MSM photodetectors, are avoided. The high frequency performance measured up to 8 GHz in the time and frequency domain showed a significant reduction of the bandwidth limiting hole tail compared to standard MSM photodetectors. © 1994 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.112767
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 13
    Digitale Medien
    Digitale Medien
    Time-resolved photocurrent response of metal-semiconductor-metal photodetectors to double-pulse excitation (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 2780-2782 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The photocurrent response of a GaAs metal-semiconductor-metal (MSM) photodetector was measured after excitation with two femtosecond pulses having a variable delay Δt of 0 ps≤Δt≤100 ps. At low excitation densities the influence of the first pulse on the pulse shape of the second is negligible for Δt≥20 ps. This corresponds to a resolvable pulse train of 50 GHz repetition rate for the detectors used in our experiments. The influence of space charge effects at higher excitation density and/or lower bias could be shown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.110332
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 14
    Digitale Medien
    Digitale Medien
    Ultrafast metal-semiconductor-metal photodiodes fabricated on low-temperature GaAs (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 60 (1992), S. 627-629 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: GaAs metal-semiconductor-metal photodiodes fabricated on GaAs grown at low substrate temperatures (200 °C) have been investigated in the time domain by electro-optic sampling. It could be shown that these diodes have a faster response, a considerably reduced long time tail, and can be used at larger bias than comparable diodes produced on GaAs grown at 700 °C. Temperature-dependent measurements show that the tail can be described by hopping conductivity and disappears below 50 K.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.106574
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 15
    Digitale Medien
    Digitale Medien
    Carrier profile for In0.35Ga0.65As/GaAs multiquantum well lasers from capacitance–voltage measurements (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 1138-1140 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The carrier profile for MBE grown In0.35Ga0.65As/GaAs multiquantum well laser structures with nominally undoped and beryllium-doped active regions was determined by using the capacitance–voltage (C–V) technique at room temperature. A simple theoretical model was used to extract the impurity concentration and the quantum-well carrier density from the experimental profiles. We obtained a high carrier concentration in nominally undoped devices caused by a strong growth temperature dependent Be diffusion from the p-cladding layer, and no difference between doped samples with different nominal dopant location. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.115738
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 16
    Digitale Medien
    Digitale Medien
    Structural and carrier density dependence of carrier lifetime in InGaAs/GaAs multiple-quantum-well lasers (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 3158-3160 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The carrier lifetime in undoped and p-doped mesa and ridge waveguide In0.35Ga0.65As/GaAs multiple-quantum-well lasers is extracted from the frequency response of the spontaneous emission. The radiative recombination coefficient is found to be the same for mesa and ridge waveguide lasers, and is nearly independent of the doping level. For ridge waveguide lasers, a simple method is proposed to obtain the lateral broadening of the active region due to carrier diffusion. When the corrected active region width is considered, the threshold carrier densities for both undoped and p-doped lasers are independent of the lateral structure and cavity width. Further, the surface recombination velocity in mesa lasers is determined. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.116814
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    Demonstration of electron beam self-focusing in plasma wake fields (1990)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 2 (1990), S. 1376-1383 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In this paper, the direct observation of wake-field self-focusing of an electron beam in plasma is reported. The dynamics of beam self-pinching and the fast collisionless evolution of a Bennett-like, near-equilibrium profile are examined theoretically and computationally. The experimental results are compared to predictions of the analysis and discussed in the context of application to the plasma lens and the plasma wake-field accelerator.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.859559
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    Diffusion of ammonia on Re(001): A monolayer grating optical second harmonic diffraction study (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8277-8283 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Diffusion of ammonia was studied over the smooth Re(001) surface utilizing optical second harmonic diffraction from surface coverage grating. The decay of the first order diffraction peak as a function of surface temperature for different initial coverages was measured and then simulated by numerical solution of Fick's second diffusion equation, employing a coverage dependent diffusion constant. For the first time the second order diffracted second harmonic signal was monitored during the diffusion process, supporting the calculated initial coverage profile and the diffusion model. The resulting diffusivity D(θ)=D0exp[−Em(θ)/RT], is defined by a barrier for diffusion Em(θ)=E0−ωZθ, with activation energy at zero coverage E0=3.4±0.6 kcal/mol, D0=2.8×10−3 cm2 sec−1 and the repulsion energy between the pair of nearest neighbor molecules ω=0.2±0.06 kcal/mol. The magnitude and effect of the repulsive interactions on diffusion are compared to their strong effect on the activation energy for desorption.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.464533
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    facet.materialart.
    Unbekannt
    David Bruce Cline (2016)
    American Institute of Physics (AIP)
    Details
    Publikationsdatum: 2016-07-08
    Print ISSN: 0031-9228
    Digitale ISSN: 1945-0699
    Thema: Physik
    Publiziert von American Institute of Physics (AIP)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 20
    facet.materialart.
    Unbekannt
    Biofilm effect on soil hydraulic properties: Experimental investigation using soil-grown real biofilm (2016)
    Wiley
    Details
    Publikationsdatum: 2016-06-30
    Beschreibung: Understanding the influence of attached microbial biomass on water flow in variably saturated soils is crucial for many engineered flow systems. So far, the investigation of the effects of microbial biomass has been mainly limited to water-saturated systems. We have assessed the influence of biofilms on the soil hydraulic properties under variably-saturated conditions. A sandy soil was incubated with Pseudomonas Putida and the hydraulic properties of the incubated soil were determined by a combination of methods. Our results show a stronger soil water retention in the inoculated soil as compared to the control. The increase in volumetric water content reaches approximately 0.015 cm 3 cm −3 but is only moderately correlated with the carbon deficit, a proxy for biofilm quantity, and less with the cell viable counts. The presence of biofilm reduced the saturated hydraulic conductivity of the soil by up to one order of magnitude. Under unsaturated conditions, the hydraulic conductivity was only reduced by a factor of four. This means that relative water conductance in biofilm-affected soils is higher compared to the clean soil at low water contents, and that the unsaturated hydraulic conductivity curve of biofilm-affected soil cannot be predicted by simply scaling the saturated hydraulic conductivity. A flexible parameterization of the soil hydraulic functions accounting for capillary and non-capillary flow was needed to adequately describe the observed properties over the entire wetness range. More research is needed to address the exact flow mechanisms in biofilm-affected, unsaturated soil and how they are related to effective system properties. This article is protected by copyright. All rights reserved.
    Print ISSN: 0043-1397
    Digitale ISSN: 1944-7973
    Thema: Architektur, Bauingenieurwesen, Vermessung , Geographie
    Publiziert von Wiley im Namen von American Geophysical Union (AGU).
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...