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
    Site transfer of Si in GaAs after heavy ion MeV implantation and annealing (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 2692-2699 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electrical and optical properties of n-type and p-type epitaxial GaAs layers have been studied after MeV implantation of heavy (Xe and Er) ions. All implanted layers were highly resistive immediately after implantation. Annealing to only moderate temperature (725 °C) recovered the as-grown electrical properties of beryllium-doped p-type layers. However, after annealing silicon-doped n-type layers, we observe a dramatic change from the as-grown carrier profiles. After anneal, the silicon-doped, n-type layers became conductive but the carrier profiles were markedly different from the as-grown material. A significant thickness of the implanted portion of the epitaxial layers shows distinct p-type conductivity after annealing. We have correlated this p-type activity with a transfer of silicon from the gallium sublattice (SiGa) to the arsenic sublattice (SiAs). The site transfer is viewed to result from the altered thermodynamics governing site occupancy during annealing of Si in GaAs under the unique damage conditions produced by heavy ion MeV implantation. Additionally, the observed thermal stability of the site transfer process above 875 °C may have implications for implantation isolation techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Growth of Er-doped silicon using metalorganics by plasma-enhanced chemical vapor deposition (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 551-558 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Epitaxial growth of Er-doped silicon films has been performed by plasma-enhanced chemical vapor deposition at low temperature (430 °C) using an electron cyclotron resonance source. The goal was to incorporate an optically active center, erbium surrounded by nitrogen, through the use of the metalorganic compound tris (bis trimethyl silyl amido) erbium. Films were analyzed by Rutherford backscattering spectrometry, secondary ion mass spectroscopy, and high resolution x-ray diffraction. The characteristic 1.54 μm emission was observed by photoluminescence spectroscopy. Previous attempts to incorporate the complex (ErO6) using tris (2,2,6,6-tetramethyl- 3,5-heptanedionato) erbium (III) indicated that excessive carbon contamination lowered epitaxial quality and reduced photoluminescent intensity. In this study, chemical analysis of the films also revealed a large carbon concentration, however, the effect on epitaxial quality was much less destructive. A factorial design experiment was performed whose analysis identified the key processing parameters leading to high quality luminescent films. Hydrogen was found to be a major cause of crystal quality degradation in our metalorganic plasma-enhanced process. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362759
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Erbium-doped silicon films grown by plasma-enhanced chemical-vapor deposition (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 6241-6248 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Epitaxial growth of erbium-doped silicon films has been performed by plasma-enhanced chemical vapor deposition using an electron-cyclotron-resonance source. The goal was to incorporate erbium as an optically active center (ErO6) through the use of metal-organic dopant sources. The characteristic 1.5 μm emission was observed by photoluminescence. Chemical analysis of the film revealed, however, that the organic ligands were decomposing and contributing to the carbon contamination of the films. Analysis of the molecular flux to the substrate indicated that the metal-organic compound used, tris(2,2,6,6-tetramethyl-3-5-heptanedionato)erbium(III), was most likely to decompose, and supply unbonded atomic erbium and not the optical active species, ErO6. Excessive carbon contamination lowered epitaxial quality and reduced the photoluminescent intensity. Photoluminescent intensity was improved by a 600 °C anneal but was strongly quenched by a 900 °C anneal. The low-temperature anneal improved crystal quality, and the high-temperature anneal resulted in silicide formation. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360571
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ion implantation into (x11)A-oriented InP and GaAs (x≤4) (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 7774-7778 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Si, Ge, and Be implantations were performed into (x11)A-oriented semi-insulating InP and GaAs substrates for x≤4. For comparison some of the implantations were also performed into (110)- and (100)-oriented substrates. For 200 keV/5×1013 cm−2 Si and 200 keV/3×1013 cm−2 Ge implants after 850 °C/7 s annealing, the InP is always n type with similar sheet resistance independent of the substrate orientation. No in-diffusion of Si or Ge was observed after annealing for any substrate orientation. Similar behavior was observed for Si implants in GaAs and for Si/B co-implants in both InP and GaAs. Photoluminescence measurements were performed on the Si- and Si/B-implanted InP and GaAs. For 30 keV/1.5×1014 cm−2 Be implants in both InP and GaAs, the in-diffusion of Be in (311)A-oriented substrates is less compared to the (100) material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356612
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Photoionization spectroscopy of traps in GaN metal-semiconductor field-effect transistors (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 2843-2852 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of the spectral and intensity dependences of the optically-induced reversal of current collapse in a GaN metal-semiconductor field-effect transistor (MESFET) have been compared to calculated results. The model assumes a net transfer of charge from the conducting channel to trapping states in the high-resistivity region of the device. The reversal, a light-induced increase in the trap-limited drain current, results from the photoionization of trapped carriers and their return to the channel under the influence of the built-in electric field associated with the trapped charge distribution. For a MESFET in which two distinct trapping centers have been spectrally resolved, the experimentally measured dependence upon light intensity was fitted using this model. The two traps were found to have very different photoionization cross-sections but comparable concentrations (4×1011 cm−2 and 6×1011 cm−2), suggesting that both traps contribute comparably to the observed current collapse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1287127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Observation of deep traps responsible for current collapse in GaN metal–semiconductor field-effect transistors (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 4016-4018 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Deep traps responsible for current collapse phenomena in GaN metal–semiconductor field-effect transistors have been detected using a spectroscopic technique that employs the optical reversibility of current collapse to determine the photoionization spectra of the traps involved. In the n-channel device investigated, the two electron traps observed were found to be very deep and strongly coupled to the lattice. Photoionization thresholds for these traps were determined at 1.8 and at 2.85 eV. Both also appear to be the same traps recently associated with persistent photoconductivity effects in GaN. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.125523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Current collapse and the role of carbon in AlGaN/GaN high electron mobility transistors grown by metalorganic vapor-phase epitaxy (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 3527-3529 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The two deep traps responsible for current collapse in AlGaN/GaN high electron mobility transistors grown by metalorganic vapor-phase epitaxy have been studied by photoionization spectroscopy. Varying the growth pressure of the high resistivity GaN buffer layer results in a change in the deep trap incorporation that is reflected in the observed current collapse. Variations in the measured trap concentrations with growth pressure and carbon incorporation indicate that the deepest trap is a carbon-related defect, while the mid-gap trap may be associated with grain boundaries or dislocations. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1418452
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Evidence of donor–acceptor pair recombination from a new emission band in semiconducting diamond (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 64 (1994), S. 2136-2138 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Steady state and time resolved photoluminescence studies of type IIb boron-doped synthetic diamond reveal a new broad red emission band that exhibits many of the features of classic donor–acceptor pair recombination. This recombination is thought to be between an as-yet unidentified neutral donor, possibly nitrogen related, approximately 3.6 eV below the conduction band edge and neutral boron acceptors at 0.37 eV above the valence band edge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.111710
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Photoluminescence and magnetic resonance studies of Er3+ in MeV ion-implanted GaAs (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 502-504 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of post-implantation annealing have been studied in MeV Er-implanted GaAs by monitoring the Er3+ electron paramagnetic resonance (EPR) signal as well as the Er3+ and near-band-edge photoluminescence (PL) spectra as a function of the anneal temperature. Er3+ PL is observed from several distinct Er sites in the annealed material. In addition, the observed dependences upon anneal temperature suggest that the Er3+ PL is emitted from centers that are not in the Er3+ state at equilibrium. Absolute EPR measurements of the Er3+ concentration indicate that only a small fraction (〈0.1%) of the Er in the sample is Er3+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.104621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Epithelial differentiation and taste buds in the soft palate of the monkey, Macaca irus (1979)
    Springer
    Cell & tissue research 196 (1979), S. 181-188 
    Details
    ISSN: 1432-0878
    Keywords: Oral epithelium ; Epithelial differentiation ; Taste buds ; Soft palate ; Monkey (Macaca irus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Mit einer Kombination licht- und elektronenmikroskopischer Untersuchungstechniken wurde das Auftreten, die Anordnung und die Struktur von Geschmacksknospen in der oralen Mukosa des weichen Gaumens von Macaca irus untersucht. Geschmacksknospen treten in Gruppen auf; sie finden sich ausschließlich innerhalb von 0.15 bis 0.3mm großen, runden Inseln keratinisierenden Epithels, die in das normalerweise nichtkeratinisierende Epithel eingebettet sind. Die Topographie, Konfiguration und Struktur dieser epithelialen Inseln und ihrer Geschmacksknospen wird beschrieben. Die Frage einer entwicklungsgeschichtlichen und funktionellen Beziehung zwischen dem Differenzierungsmuster und den Eigenschaften des Epithels und der Funktion der Geschmacksknospen wird diskutiert.
    Notes: Summary A combination of light, transmission and scanning electron microscopy was employed to demonstrate the occurrence, arrangement and structure of taste buds in the oral mucosa of the soft palate of monkeys (Macaca irus). Taste buds are found in aggregates confined to 0.15 to 0.3 mm wide, round islands of keratinizing epithelium embedded in the normally non-keratinizing integument. Topography, configuration and structure of these epithelial islands and their taste buds are described, and the question of a developmental and functional interrelationship between epithelial differentiation and properties, and taste bud function is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236359
    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...