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  • 1
    Electronic Resource
    Electronic Resource
    Reduction of interface phonon modes using metal-semiconductor heterostructures (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 2338-2342 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Based on a simplified analysis of perfectly conducting metals, it has been suggested qualitatively that establishing metal-semiconductor interfaces at the heterojunctions of polar semiconductor quantum wells introduces a set of boundary conditions that dramatically reduces or eliminates unwanted carrier energy loss caused by interactions with interface longitudinal-optical (LO) phonon modes. In this article, it is theoretically demonstrated that comparable reductions in LO phonon scattering strengths may be achieved for metal-semiconductor structures with metal having realistic conductivities and Thomas–Fermi screening lengths.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353139
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  • 2
    Electronic Resource
    Electronic Resource
    Hot-phonon effects on electron transport in quantum wires (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 5145-5149 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hot (nonequilibrium) phonon effects on electron transport in rectangular GaAs/AlAs quantum wires have been investigated by a self-consistent Monte Carlo simulation. Confinement and localization of optical phonons have been taken into account. We have demonstrated that at room temperature hot optical phonons lead to a significant increase in electron drift velocity. This hot-phonon drag effect is due to the strongly asymmetric nonequilibrium phonon distribution. As a result, phonon absorption for forward transitions (electron gains momentum along electric field) is enhanced, whereas absorption for backward transitions (electron gains momentum against electric field) is suppressed. At low temperatures diffusive heating of electrons by hot phonons dominates over hot-phonon drag and the electron drift velocity decreases. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363496
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  • 3
    Electronic Resource
    Electronic Resource
    Optical properties of ultrathin GaAs/AlAs quantum well structures with an electric field (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 8675-8681 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A theoretical study of the optical properties of GaAs/AlAs quantum well structures in the presence of an electric field is presented. In the first part of the article, interband transitions from the valence band to the conduction band are studied near the type-I to type-II transition point. In the second part, the effect of the electric field on intersubband transitions within the conduction band is considered. The band structure is calculated using a second-nearest-neighbor empirical sp3 tight binding method including spin–orbit effects. Interband and intersubband transition energies, optical matrix elements, and absorption coefficients are given as functions of the electric field. It is shown that the optical properties of these structures can be modified significantly with field near the anticrossing point. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362493
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  • 4
    Electronic Resource
    Electronic Resource
    Simulation of electronic properties and capacitance of quantum dots (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 3267-3276 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The chemical potential and the capacitance of a 2D circular model quantum dot have been investigated for GaAs, InSb, and Si material parameters, covering a range from a few nanometers to micrometer dimensions. The Schrödinger equation has been solved self-consistently, with the inclusion of many-body effects, using a local density approximation as well as the optimized Krieger-Li-Iafrate exchange potential. Gate structures are included by use of the method of images. We have focused on quantum deviations from classical electrostatic capacitive behavior and found such deviations to be significant even for the material parameters of silicon for feature sizes smaller than 30 nm. The most striking features of quantum dot capacitance are signatures of the dot symmetry analogous to the orbital grouping in atoms: we find structure in the dot capacitance arising from quantum effects in correspondence with the filling of each group of energy-degenerate orbitals. We also cover the influence of a magnetic field perpendicular to the dot plane and we report some results for the chemical potential vs magnetic field and electron number, assuming an effective g-factor corresponding to the one of bulk gallium arsenide. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358680
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  • 5
    Electronic Resource
    Electronic Resource
    Electron interaction with confined acoustic phonons in cylindrical quantum wires via deformation potential (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 2815-2822 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of phonon confinement on electron–acoustic-phonon scattering is studied in cylindrical semiconductor quantum wires. In the macroscopic elastic continuum model, the confined-phonon dispersion relations are obtained for several crystallographic directions with the two cardinal boundary conditions: free-surface and clamped-surface boundary conditions. The scattering rates due to the deformation potential interaction are obtained for these confined phonons and are compared with those of bulk-like phonons for a number of quantum wire materials. The results show that the inclusion of acoustic phonon confinement effects may be crucial for calculating accurate low-energy electron scattering rates in nanostructures. It is also demonstrated that the scattering rates may be significantly influenced by the direction of phonon propagation, especially for low-energy electrons. Furthermore, it has been found that there is a scaling rule governing the directional dependence of the scattering rates: the directions characterized by small Poisson ratios exhibit large scattering rates. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363199
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  • 6
    Electronic Resource
    Electronic Resource
    Application of superlattice bandpass filters in 10 μm infrared detection (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 1533-1535 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Recently, experimental evidence has revealed that the energy distribution of the dark current in a typical multiple quantum well GaAs infrared detector is extremely broad, in contrast to the narrowly distributed photocurrent. In this letter, we present the current transfer ratio of an infrared hot-electron transistor with a superlattice collector filter. From the current transfer characteristics, we demonstrate that the superlattice is able to collect electrons with specific energy against a broad background. The energy filtering characteristics can be attributed to the underlying band structure of the superlattice. When the filter is applied to infrared radiation detection, the detectivity of the transistor is improved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.105169
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  • 7
    Electronic Resource
    Electronic Resource
    Thermally stimulated hot-electron spectroscopy (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 57 (1990), S. 76-78 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We introduce and utilize a novel method to characterize the energy levels of quantum well structures. In this method, thermal stimulation is utilized to excite conduction electrons from the lowest subband to the higher subbands of the structure while the structure is subjected to an applied voltage. The energy distribution of the electrons injected from this structure is then analyzed by a quantum barrier placed adjacent to the structure. This spectroscopic method results in the identification of the energy levels and the electron transport mechanisms of the structure in question. In this letter, excitation spectra from three different quantum well structures are presented to demonstrate the utility of this technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.103583
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  • 8
    Electronic Resource
    Electronic Resource
    Realization of high mobility in inverted AlxGa1−xAs/GaAs heterojunctions (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 52 (1988), S. 2037-2039 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report reproducible realization of GaAs/Al0.25 Ga0.75 As(100) inverted heterojunctions with liquid-nitrogen electron mobilities in excess of 105 cm2 /(V s). This is made possible through use of reflection high-energy electron-diffraction (RHEED) intensity dynamics determined optimized growth conditions, but without the use of short-period superlattices as buffers or spacer layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99574
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  • 9
    Electronic Resource
    Electronic Resource
    Self-consistent resonant states and phase coherence in a wide double-barrier structure (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 359-361 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present experimental tunneling current-voltage characteristics for a wide (1040-A(ring)-wide well) double-barrier structure; concomitant differential conductance data show a series of oscillations in the differential conductance-voltage characteristics. By using a self-consistent analysis, we show that the observed conductance oscillations arise predominantly from the structure of the local density of states of the confining well rather than the density of states of the global structure; this result shows that there is a lack of long-range phase coherence for the tunneling electrons in this structure. Also, in this analysis we determine the importance of the band nonparabolicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.100969
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  • 10
    Electronic Resource
    Electronic Resource
    10 μm infrared hot-electron transistors (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 57 (1990), S. 1348-1350 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A new hot-electron transistor for 10 μm infrared radiation detection is presented and discussed. The device utilizes an infrared sensitive GaAs/AlGaAs multiple quantum well structure as emitter, a wide quantum well as base, and a thick quantum barrier placed in front of the collector as an electron energy high pass filter. The energy filter selectively permits the higher energy photocurrent to pass to the collector; the lower energy dark current is rejected by the filter, and is drained through the base. The device detectivity, as noted by the collector photocurrent measurements, is much enhanced in comparison with companion infrared photoconductive devices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.103480
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