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
  • 1
    Digitale Medien
    Digitale Medien
    Excitation of optical transitions in the InxGa1−xAs-GaAs quantum well system by the free exciton in the barrier (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 1453-1455 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In the InxGa1−xAs-GaAs coupled double quantum well system the free exciton in the GaAs barrier is directly coupled to the symmetric heavy-hole free exciton in the quantum well. In contrast the free exciton in the barrier does not couple to the symmetric light-hole free exciton in the quantum well, or to Landau levels associated with the lowest energy conduction and valence subband levels. These results are explained by momentum conservation rules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.354887
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Alloy scattering in p-type AlxGa1−xAs (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 260-266 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The hole mobility of Be-doped ( ∼ 2 × 1017 cm−3) AlxGa1−xAs, for x=0–1, is analyzed both theoretically and experimentally. Alloy scattering is very important, and in fact reduces the hole mobility from 150 to less than 90 cm2/V s at x=0.5. The main parameter in the alloy scattering formulation, the alloy potential Eal, is found to be about 0.5 eV for p-type AlxGa1−xAs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.350752
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Electrical and structural study of partially relaxed Ga0.92In0.08As(p+)/ GaAs(n) diodes (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 1303-1309 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The effects of in-plane lattice mismatch have been studied for Ga0.92In0.08As(p+)/GaAs(n)/GaAs(n+) diodes. Different in-plane mismatch at the p–n junction was introduced by a variation of the GaInAs layer thickness (h=0.1, 0.25, 0.5, and 1 μm). Capacitance-voltage (C-V) measurements with different frequencies show a higher-frequency dispersion for a greater lattice-mismatched sample. From the frequency dependence of the C-V curve, single-level charged interface-state density (Ns) was estimated using the effective parallel capacitance and conductance components. The average charged interface density Nss was also estimated using Voltage-intercept (Vint) method. Nss shows a linear dependence on the in-plane mismatch. The charged interface state density is approximately 2.7 Δa(parallel)/a30 for partially lattice-relaxed heterojunctions. For the 1 μm sample, the forward I-V characteristic shows quasi-Fermi level pinning effect. Admittance spectroscopy measurement gives an equilibrium Fermi energy at about Ev+0.36 eV with hole capture cross section cp=2.7×10−15 cm2 for the 1 μm sample and at Ev+0.21 eV and cp=2.4×10−16 cm2 for the 0.5 μm sample.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.346699
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Effects of lattice mismatch and thermal annealing on deep traps and interface states in Ga0.92In0.08As(n+)/GaAs(p) heterojunctions (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 4362-4366 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The effects of the lattice-mismatch-induced defects on deep level traps in Ga0.92In0.08As(n+)/GaAs(p) heterojunction diodes have been studied by means of various deep level transient spectroscopy techniques and the frequency-dependent capacitance-voltage (C-V-f) characteristics. Three hole traps at 0.58, 0.42, and 0.27 eV were observed. We attribute the 0.42 eV trap to Cu impurity, the 0.58 eV trap to VGa or Fe, and the 0.27 eV trap to a complex associated with the 0.42 and 0.58 eV traps. Depth profiles of these hole traps in the GaAs side were measured in different lattice-mismatched samples. The depth profile data near the interface and from deep inside the bulk show evidence of impurity gettering by the mismatched interface. We also found that the concentrations of these traps were reduced by rapid thermal annealing. A U-shaped energy distribution of the interface states was obtained from the C-V-f measurements. For an in-plane mismatch greater than 0.25%, the interface state density shows no obvious dependence on the in-plane lattice mismatch, while at smaller mismatch the interface state density increases with increasing mismatch. The interface state density was on the order of 1011 cm−2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.352821
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Optical absorption of the intersubband transitions in GaAs/Al0.4Ga0.6As multiple quantum wells with superlattice barriers (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3105-3107 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The optical absorption of intersubband transitions in n-type GaAs/Al0.4Ga0.6As multiple quantum wells with superlattice barriers is studied as a function of temperature. The room-temperature spectrum shows a strong intersubband transition at 118.64 meV (10.45 μm) and a shoulder at 137.00 meV (9.05 μm). A broad transition is also observed at 204.6 meV (6.06 μm). The 118.64 meV intersubband transition exhibits a blue shift (∼5.33 meV) as the temperature is decreased from 295 to 4.2 K. The intensity of this transition is increased dramatically while the intensity of the shoulder observed at 137.00 meV is reduced as the temperature is decreased. Theoretical calculations based on a self-consistent k⋅p model which include many-body effects of Hartree, exchange-correlation, depolarization, and vertex effects indicate that the 118.64 meV intersubband absorption is due to the electronic transition between the ground and excited states in the well. On the other hand, the shoulder seems to correspond to a transition between the ground state and the miniband formed in the superlattice barrier.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.352998
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Annealing dynamics of molecular-beam epitaxial GaAs grown at 200 °C (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 306-310 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: By separating a 2-μm-thick molecular-beam-epitaxial GaAs layer grown at 200 °C from its 650-μm-thick substrate, we have been able to obtain accurate Hall-effect and conductivity data as functions of annealing temperature from 300 to 600 °C. At a measurement temperature of 300 K, analysis confirms that hopping conduction is much stronger than band conduction for all annealing temperatures. However, at higher measurement temperatures (up to 500 K), the band conduction becomes comparable, and a detailed analysis yields the donor and acceptor concentrations and the donor activation energy. Also, an independent absorption study yields the total and charged AsGa concentrations. Comparisons of all of these quantities as a function of annealing temperature TA show a new feature of the annealing dynamics, namely, that the dominant acceptor (probably VGa related) strongly decreases and then increases as TA is increased from 350 to 450 °C. Above 450 °C, ND, NA, and [AsGa] all decrease, as is known from previous studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.354108
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Analytical two-layer Hall analysis: Application to modulation-doped field-effect transistors (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 311-314 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The classical magnetic-field-dependent Hall coefficient and conductivity equations are inverted to give the mobilities μ1 and μ2 and carrier concentrations n1 (or p1) and n2 (or p2) in two degenerate bands. The two-band solution holds for arbitrary magnetic-field strength as long as quantum effects can be ignored (i.e., kT(approximately-greater-than)(h-dash-bar)eB/m*), and it is argued that the analysis can also be applied to two separate layers up to reasonable field strengths. The results are used to determine the two-dimensional electron gas mobility and carrier concentration in a modulation-doped field-effect transistor with a highly doped cap layer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.354109
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Mechanisms for GaAs surface passivation by a molecular beam epitaxial cap layer grown at 200 °C (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 5981-5984 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A thin, undoped, molecular beam epitaxial (MBE) GaAs cap layer grown on top of an n-type conductive layer significantly reduces the free-electron depletion from the latter. By analyzing electron transfer to surface, interface, and bulk acceptor states in the cap, as a function of cap thickness, we show that either (1) the usual EC−0.7 eV surface states are absent, (2) a dense donor near EC−0.4 eV exists or (3) a high donor interface charge (∼5×1012 cm−2) is present. Any of these conclusions constitutes an important new aspect of low-temperature MBE GaAs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.350450
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Arsenic for antimony exchange on GaSb, its impacts on surface morphology, and interface structure (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 329-337 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We quantify the rates and total amounts of the arsenic for antimony exchange on both the Sb-terminated and Ga (or In)-terminated GaSb (001) surfaces using in situ real time line-of-sight mass spectrometry (LOS-MS) during molecular beam epitaxy. On the Sb-terminated GaSb (001) surface, an As for Sb exchange is observed to occur at all values of incident As2 flux considered. At high substrate temperature, three-dimensional (3D) nanometer-sized clusters from as a consequence of As/Sb exchange and lattice mismatch strain between GaAs and GaSb. The 3D clusters are found to have lateral dimensions of ∼10–30 nm and heights of 1–3 nm by atomic force microscopy (AFM). By contrast, at lower substrate temperatures a two-dimensional surface morphology is maintained, and AFM reveals an array of atomically flat terraces. On the surface terminated by one monolayer (ML) of Ga or In, there exists a critical As2 flux below which the As/Sb exchange is greatly diminished. The net amounts of Sb leaving the surface during one period of InAs/GaSb type-II superlattice growth are measured in real time by LOS-MS and estimated to be in the range of 0–0.4 ML for the various conditions used. By supplying only an As2 beam to a GaSb surface covered by InAs, the Sb riding over the InAs layer is replaced by arsenic and the total amount of such Sb is measured. The amount of Sb riding on the InAs can be as large as 0.8 ML for the first 1 ML of InAs and it gradually decreases to zero as the number of InAs monolayer increases. X-ray diffraction data show that all the InAs/GaSb superlattices coherently match with the GaSb substrate in the growth plane. The average lattice constant along the growth direction reduces with decreasing Sb mole fraction shown by the increased Sb desorption signal. Using the information on As/Sb exchange and Sb riding on the InAs surface, we predict an average lattice constant along the growth direction to be consistent with the measured one to within 2×10−4. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.370733
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    A comparison of electrochemical capacitance-voltage measurements with numerical simulations for pseudomorphic high electron mobility transistor structures (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 2531-2536 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Electrochemical capacitance-voltage (EC-V) profiling is simulated numerically and the results compared with EC-V measurements for AlxGa1−xAs/InyGa1−yAs pseudomorphic high electron mobility transistor (p-HEMT) structures. The electrostatic potential is calculated at each etch step by solving the Poisson equation subject to surface pinning. The mobile charge is calculated within the Thomas-Fermi approximation. The calculated potential then forms the basis for the numerical EC-V, enabling the capacitance and apparent electron concentration to be computed. The reconstructed electron distribution has been compared with actual EC-V measurements on actual p–HEMT structures. The results affirm the ability of experimental EC-V to separate detailed features in the electron distribution, such as electrons localized in the δ layer and channel of p–HEMTs. Essentially, the reconstructed electron distribution is a warped version of the true distribution as determined from a self-consistent k⋅p calculation. In δ-doped p–HEMTs, for example, the separation between the charges in the δ layer and channel is less than the actual separation. This trend appears to agree with measured EC-V results. Subject to control over the etching uniformity, experimental EC-V should be capable of delineating detailed features in the electron distribution. Numerical EC-V has also been compared with standard capacitance-voltage (C-V) profiling. The reconstructed numerical C-V electron distribution agrees well with the numerical EC-V distribution. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.360108
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...