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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3514-3521 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The structural properties of GaAs, InAs, GaP, and InP implanted by Fe or Ti at 150 keV/400 keV and doses of 1012–1×1015 cm−2 and the depth distribution of the implants are comparatively studied before and after annealing with and without a Si3N4 cap. Results of Rutherford backscattering, x-ray double-crystal diffractometry, and secondary-ion mass spectroscopy experiments are presented. Fe redistributes strongly in all materials upon annealing, Ti does not redistribute at all. The driving force of redistribution of Fe is not classical diffusion but reaction with implantation-induced defects and stoichiometric imbalances. The actual defect chemistry of the as-implanted arsenides is found to be fundamentally different from the as-implanted phosphides since in the latter case the mass ratio of the constituents is much larger and the specific energy for amorphization is much lower. Consequently, redistribution of Fe in the phosphides and the arsenides differs qualitatively from each other.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 1 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This paper presents a review devoted to the problem of how optical and structural properties of quantum-well heterostructures (QWH) can be correlated in detail, and how these properties may be connected with the parameters of the epitaxial growth process. It demonstrates how luminescence techniques, mainly photoluminescence (PL) and cathodoluminescence imaging (CLI), may be used for evaluation of the structural disorder on the atomic scale, which occurs at the growth surfaces creating the interfaces of the QWH. The physics of the excitonic luminescence in QWH (theory and experiment) is presented in detail in the first part of the review. This is followed by a comprehensive discussion of experimental aspects (hardware and software) of the luminescence techniques, as applied for studying QWH grown by molecular-beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE). The specific features of both the epitaxial growth techniques, when used for growing QWH are presented in the next part of this review. Finally, the possibilities of application of PL and CLI to studies on growth of QWH by MBE and MOVPE are demonstrated on a couple of selected examples. The review concludes with a short discussion on possible interpretation mistakes which may occur when one applies the CLI to studies of interfaces in QWH without taking into account the basic parameters of the excitonic luminescence lines creating the CL images of the relevant interfaces.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 8154-8157 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The crystalline quality of AlxGa1−xAs grown on a V-grooved (001) GaAs substrate is characterized by low-temperature cathodoluminescence and transmission electron microscopy. High-crystalline perfection visualized by narrow neutral donor bound exciton luminescence is attained above the groove. Growth of (Al, Ga) As in the groove takes place without significant change of the aluminium distribution. An order of magnitude increase of silicon acceptor concentration induced by As-vacancy creation is detected at the interface n-GaAs substrate/V groove. Transmission electron microscopy pictures taken from sample cross sections do not show any kind of defects in the groove.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 2499-2500 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The relaxation oscillation frequency of p-substrate buried crescent InGaAsP lasers is measured as a function of the output power in the switched-on state. The lasers are excited by a steplike current pulse at room temperature. The highest resonance frequency observed for a 350-μm long cavity is 12.1 GHz equivalent to an intrinsic 3-dB cutoff frequency of 18.8 GHz at an optical power of 9 mW/facet according to an injection current of 3.8 times threshold current, this is so far the best ever published value for a p-substrate laser.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 8641-8646 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report a novel measurement technique for the wide-band determination of the frequency response of photodetectors. It is based upon the accurate measurement of the photocurrent noise spectra under illumination with a light-emitting diode. The high sensitivity of −200 dBm/Hz within a frequency regime from 10 MHz to 1.6 GHz renders it particularly attractive for investigating the response behavior at low optical input levels and for characterizing frequency-dependent gain phenomena. The practical potential of the method is illustrated by applying it to various types of InGaAs-based photodetectors (p-i-n and avalanche photodiodes and metal-semiconductor-metal photodetectors).
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 4825-4830 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The distribution of Fe implanted at medium (1–4×1014 cm−2) and low (2×1012 cm−2) doses into InGaAs and annealed with or without a cap is investigated and the degree of compensation of such implanted regions is assessed. Secondary ion mass spectrometry profiles of low dose implanted Fe reveal a substantial role of the capping layer. Fe concentrations below as well as above the estimated metal vacancy concentration produced by implantation are observed. The effect of the cap strongly depends on the wet chemical surface preparation before insulator deposition. A correlation of the magnitude of the Fe accumulation at the InGaAs surface with defect related photoluminescence intensity is established. On the basis of the substitutional-interstitial diffusion model the barrier effects of the various caps for host and dopant atoms are analyzed. The best semi-insulating properties were obtained for plasma enhanced chemical vapor deposition SiO2 caped samples using a H2SO4:H2O2:H2O=1:1:125 surface preparation before deposition resulting in a 53% incorporation of Fe. A high electrical activation is proved directly by capacity-voltage profiles.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present results of a comparative study of the time-dependent luminescence properties of multiple quantum well structures with varying barrier widths which are embedded in the active area of a light-emitting device. The carrier kinetics is investigated by different experimental approaches: Cathodoluminescence and electroluminescence experiments where excitation is on/off-modulated for the purpose of time-resolved measurements and time-resolved electroluminescence experiments in the small signal regime which allow for observation of the carrier kinetics under flatband conditions. Due to the exact determination of the excess carrier density the latter technique provides a sensitive tool for a precise estimation of the mono- and bimolecular recombination coefficients. Comparison with light output data yields radiative and nonradiative parts. We find that coupling of quantum wells dramatically favors nonradiative interface recombination as expected from a theoretical model accounting for the superlattice wavefunctions. On the other hand, the bimolecular recombination rate remains unaltered even when the barrier width is lowered from 18 to 0.9 nm. In contrast, on/off modulated experiments reveal that luminescence decay is strongly influenced by carrier drift out of the active area. A barrier width dependent carrier mobility in growth direction accounts for these results if phonon assisted hopping rather than Bloch transport is presumed. Thus, an estimation of device quality of quantum well light emitters by conventional time-resolved cathodo- (or photo-) luminescence experiments is found to be possible if internal field induced carrier drift processes are taken into account.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Deep levels in liquid-encapsulation Czochralski (LEC) grown p-type InP:Fe codoped with Zn have been investigated by means of temperature-dependent Hall-effect (TDH), deep-level transient spectroscopy (DLTS), calorimetric absorption spectroscopy, and electron spin resonance measurements. Although a dominant deep hole trap is revealed both by DLTS and TDH measurements in the vicinity of the valence band edge at EV+0.2 eV, the spectroscopic analysis unambiguously invalidates previous speculations on the existence of a second energy level of the isolated iron impurity in the band gap of InP, i.e., a Fe4+/Fe3+ donor level. From the axial concentration profile and a comparison with a LEC-grown p-type InP crystal doped with Zn only it seems that the trap is not even iron-related in contrast to tentative assignments often found in the literature. Native or Zn-related defects which depend on the particular growth conditions used are assumed to account for this level.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 5699-5702 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Low leakage current p+/n step junctions with mechanically stable ohmic contacts to p+ layer are fabricated on n-InP wafers simultaneously by a simple procedure consisting of vacuum evaporation of Ni, Zn, and Au followed by a short heat treatment at 340 °C. Current-voltage and capacitance-voltage measurements, secondary ion mass spectroscopy, and deep level transient spectroscopy are employed to characterize the diodes fabricated and to understand their structure.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 2604-2609 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The redistribution of Fe and Ti implanted into InP and its recrystallization is studied using 〈m1;37.6p〉various thermal annealing techniques. Fe and Ti profiles are measured by secondary-ion mass spectroscopy and recrystallization by Rutherford backscattering channeling. Ti shows absolutely superior thermal stability under any circumstances as compared to Fe. Iron always accumulates at the surface and at a depth of approximately twice the projected range Rp. After high-dose implantation Fe additionally accumulates in the 0.8Rp region. At similar doses Ti still shows no diffusion and only faint accumulation between the surface and Rp.
    Type of Medium: Electronic Resource
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