Search Results - (Author, Cooperation:T. Y. Chang)

Showing 1 - 20 results of 48, query time: 0.24s Refine Results
  1. 1
    W. Yang ; Y. Bai ; Y. Xiong ; J. Zhang ; S. Chen ; X. Zheng ; X. Meng ; L. Li ; J. Wang ; C. Xu ; C. Yan ; L. Wang ; C. C. Chang ; T. Y. Chang ; T. Zhang ; P. Zhou ; B. L. Song ; W. Liu ; S. C. Sun ; X. Liu ; B. L. Li
    Nature Publishing Group (NPG)
    Published 2016
    Staff View
    Publication Date:
    2016-03-17
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Acetates/*pharmacology/therapeutic use ; Acetyl-CoA C-Acetyltransferase/antagonists & ; inhibitors/deficiency/genetics/metabolism ; Animals ; Atherosclerosis/drug therapy ; CD8-Positive T-Lymphocytes/*drug effects/*immunology/metabolism ; Cell Membrane/drug effects/metabolism ; Cholesterol/*metabolism ; Esterification/drug effects ; Female ; Immunological Synapses/drug effects/immunology/metabolism ; Immunotherapy/*methods ; Male ; Melanoma/*drug therapy/*immunology/metabolism/pathology ; Mice ; Programmed Cell Death 1 Receptor/antagonists & inhibitors/immunology ; Receptors, Antigen, T-Cell/immunology/metabolism ; Signal Transduction/drug effects ; Sulfonic Acids/*pharmacology/therapeutic use
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Staff View
    Publication Date:
    2018-09-05
    Publisher:
    American Physical Society (APS)
    Print ISSN:
    0031-9007
    Electronic ISSN:
    1079-7114
    Topics:
    Physics
    Keywords:
    Atomic, Molecular, and Optical Physics
    Published by:
    http://www.aps.org/

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Staff View
    Publication Date:
    2018-08-09
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Electronic ISSN:
    2375-2548
    Topics:
    Natural Sciences in General
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    P Y Hsieh, L F W Chang, T Y Yu and K C Wu
    Institute of Physics (IOP)
    Published 2018
    Staff View
    Publication Date:
    2018-11-06
    Publisher:
    Institute of Physics (IOP)
    Print ISSN:
    1755-1307
    Electronic ISSN:
    1755-1315
    Topics:
    Geography
    Geosciences
    Physics
    Published by:
    http://www.iop.org/

    Latest Papers from Table of Contents or Articles in Press
  5. 5
    Williams, M. D. ; Feuer, M. D. ; Shunk, S. C. ; Sauer, N. J. ; Chang, T. Y.

    [S.l.] : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We demonstrate the operation of a vacuum collector–semiconductor transistor based on negative electron affinity cold cathode technology. The unique aspect of this transistor is that the collector is separated from the emitter-base junction by a vacuum drift region, yielding an intrinsic collector capacitance which is an order of magnitude lower than that for conventional bipolar transistors. The collector charging time is thus proportionally smaller. Transport in the vacuum drift region is truly ballistic and depends only on the collector-base bias, enabling a wide range of device concepts which are impossible or impractical in conventional transistors.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.350990

    Articles: DFG German National Licenses
  6. 6
    Dodabalapur, A. ; Chang, T. Y. ; Tell, B. ; Brown-Goebeler, K. F.

    [S.l.] : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We describe procedures to grow InAlAs/InGaAs and InGaAlAs/InGaAs heterojunction bipolar transistors (HBTs) on Si-implanted InP substrates by molecular beam epitaxy (MBE). The combined effects of ion implantation and annealing necessitates a significant modification of MBE growth conditions in order to obtain high quality epilayers and heterojunctions. Approximately 50% higher As4 flux is needed, especially during the initial heat cleaning step, to obtain layers with good surface morphology and HBTs with dc characteristics similar to those of HBTs grown on regular InP substrates. InGaAlAs/InGaAs HBTs grown under modified conditions on implanted and annealed InP have dc current gains of 2000 at a current density of 2 kA/cm2 . Similar MBE growth conditions can be used to grow other minority-carrier lifetime sensitive devices directly on implanted and annealed InP wafers.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.351108

    Articles: DFG German National Licenses
  7. 7
    Huang, J.-H. ; Chang, T. Y.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A method that combines capacitance-voltage and current-voltage-temperature measurements of a n+-i-n− (or p+-i-p−) heterobarrier structure for reliable determination of the band discontinuity is described. Experimental and analytical procedures for the extraction of the Fermi energies in the doped layers, the location of the flat band condition, and the determination of the barrier height at flat band are given. The effects of nonparabolicity and strain are also considered. Some potential sources of errors encountered in the conventional procedure that is based on the barrier height at zero bias are avoided in this flat band method. The application of this method and other experimental considerations are illustrated by using the strained InxGa1−xAs/In0.52Al0.48As heterointerface as a specific example. The results show that the conduction-band offset ratio, Qc, is nearly constant at 0.71 for x≤0.54 but appears to change quite abruptly to a fairly constant value of 0.82 for x≥0.58.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.357527

    Articles: DFG German National Licenses
  8. 8
    Chin, Albert ; Chang, T. Y. ; Ourmazd, A. ; Monberg, E. M.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Very high quality GaInAs/AlInAs modulation-doped heterostructures have been obtained by molecular beam epitaxy on InP oriented 6° off (110) towards the (111¯) pole. The results indicate partial ordering in the epitaxial layers and also suggest reduced background acceptor concentration. In spite of the high density of interface steps, the electron mobility obtained on the vicinal (110) substrate exceeds the state-of-the-art value obtained on (100) oriented substrates.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.104458

    Articles: DFG German National Licenses
  9. 9
    Espindola, R. P. ; Udo, M. K. ; Chu, D. Y. ; Wu, S. L. ; Ho, S. T. ; Tiberio, R. C. ; Chapman, P. F. ; Hou, H. Q. ; Chang, T. Y.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1996
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We report on the fabrication and characterization of broadband Bragg filters in microfabricated AlGaAs waveguides. Electron-beam lithography and chemically assisted ion-beam etching were used to fabricate first-order gratings with 250 nm period. Bragg filters with rejection bandwidth ∼15 nm and centered at ∼1.6 μm are demonstrated. © 1996 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.116473

    Articles: DFG German National Licenses
  10. 10
    Caridi, E. A. ; Chang, T. Y. ; Goossen, K. W. ; Eastman, L. F.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We report the first direct demonstration of a strain-generated built-in electric field in a (111) oriented strained-layer heterostructure. We present a model which describes the accommodation of the misfit strain in a lattice-mismatched quantum well, and the resulting generation of a longitudinal electric field via the piezoelectric effect. On a (111)B GaAs substrate, we grew the quantum well in the intrinsic region of a p-i-n diode such that the strain-generated electric field in the quantum well opposes the weaker built-in electric field of the diode. Under reverse bias operation, photoconductivity measurements show a quadratic blue shift of the quantum well electroabsorption peaks, in contrast to the red shifts normally observed in the quantum-confined Stark effect. The measured blue shifts demonstrate an electric field strength of 1.7×105 V/cm, which agrees with theory to within the accuracy of the measured sample characteristics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.102729

    Articles: DFG German National Licenses
  11. 11
    Zucker, J. E. ; Wegener, M. ; Jones, K. L. ; Chang, T. Y. ; Sauer, N. ; Chemla, D. S.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    With a recently developed semiconductor heterostructure it has become possible to tune continuously the electron density in multiple quantum wells. Here we demonstrate the first electro-optic waveguide intensity modulators based on this concept. We achieve a 22 dB on/off ratio for 9 V applied at 1.54 μm wavelength in a rib waveguide electroabsorption modulator. Electrorefractive devices include a waveguide Mach–Zehnder interferometer with an active length 650 μm operating at 1.58 μm wavelength with 5.4 V half-wave voltage. We show that the operating voltage can be further reduced by operating the Mach–Zehnder modulators in push-pull configuration.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.103032

    Articles: DFG German National Licenses
  12. 12
    Wegener, M. ; Chang, T. Y. ; Bar-Joseph, I. ; Kuo, J. M. ; Chemla, D. S.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We present a novel heterostructure that exhibits large electroabsorption and refraction. The structure is periodic with a stackable building block, thus it allows large contrast and waveguide operation. The mechanism used is the quenching of absorption produced by transfer of electrons from a reservoir into a quantum well. We demonstrate the principle by presenting differential absorption and refraction spectra on a ten-period device.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.101840

    Articles: DFG German National Licenses
  13. 13
    Lee, D. H. ; Li, Sheng S. ; Sauer, N. J. ; Chang, T. Y.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A high quality In0.53Ga0.47As Schottky barrier diode fabricated by using a thin graded superlattice (SL) of In0.53Ga0.47As/In0.52Al0.48As grown by molecular beam epitaxy is reported for the first time in this letter. The effective Schottky barrier heights of ∼0.71 and ∼0.60 eV were obtained for the Au- and Cr-Schottky contacts, respectively. Excellent current-voltage and capacitance-voltage characteristics were obtained for these diodes. The graded InGaAs/InAlAs SL structure allows one to circumvent the problem of carrier pileup associated with abrupt heterostructures, and hence is advantageous for forming Schottky contacts on InGaAs for high-speed optoelectronic device applications.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.101261

    Articles: DFG German National Licenses
  14. 14
    Islam, M. N. ; Sunderman, E. R. ; Bar-Joseph, I. ; Sauer, N. ; Chang, T. Y.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Using multiple quantum well (MQW) saturable absorbers, we passively mode locked a NaCl color center laser to produce transform-limited, pedestal-free pulses with τ as short as 275 fs and peak power as high as 3.7 kW. Because of exciton ionization with a 200±30 fs time constant, the MQW shows a fast absorption recovery that is comparable to our pulse widths. This fast component plays a major role in pulse shaping and may limit the pulse width. We also show that the wavelength for the short pulses can be tuned from 1.59 to 1.7 μm by choosing MQWs with different band gaps.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.100753

    Articles: DFG German National Licenses
  15. 15
    Wiesenfeld, J. M. ; Heutmaker, M. S. ; Bar-Joseph, I. ; Chemla, D. S. ; Kuo, J. M. ; Chang, T. Y. ; Burrus, C. A. ; Perino, J. S.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    High-speed waveforms (up to 20 GHz) in InGaAs/InAlAs modulation-doped field-effect transistors (FETs) are measured using 10–20 ps optical probe pulses via the quenching of the absorption in the quantum well gate channel due to Pauli exclusion. The technique is a noncontact probe of the charge density in the gate, and hence, of the logic state of the FET. This charge-sensitive probing technique is combined with voltage-sensitive electro-optic sampling to study internal dynamics of the FET. A gate channel charging time of 11 ps and a gate to drain propagation delay of 15 ps are measured.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.101672

    Articles: DFG German National Licenses
  16. 16
    Crawford, D. L. ; Taylor, G. W. ; Cooke, P. ; Chang, T. Y. ; Tell, B. ; Simmons, J. G.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1988
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Fabrication and characterization of a three-terminal self-aligned double-heterostructure optoelectronic switch in the light-emitting diode configuration are reported. Results demonstrating device switching characteristics are presented, in which switching is triggered by electrical or optical stimuli. Electrical switch-on and switch-off transitions occur in 10 ns, under electrical stimulus. Corresponding optical turn-on times of 60 ns are observed. With an optical switching energy of 0.02 fJ/μm2, an electrical switch-on transition of 4 ns is observed.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.99784

    Articles: DFG German National Licenses
  17. 17
    Goossen, K. W. ; Caridi, E. A. ; Chang, T. Y. ; Stark, J. B. ; Miller, D. A. B. ; Morgan, R. A.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We have observed room-temperature exciton blue shift with applied voltage in a 〈111〉 In0.1Ga0.9As-GaAs p-i-n multiple quantum well modulator. We have also observed optically induced bistability in a symmetric self-electro-optic effect device circuit composed of these modulators. Very large (2.5:1) ratios of photocurrent were obtained with only 0–3 V applied bias.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.102690

    Articles: DFG German National Licenses
  18. 18
    Owusu-Sekyere, K. ; Chang, A. M. ; Chang, T. Y.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1988
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A new, simplified process has been developed for fabricating submicron AlxGa1−xAs-GaAs heterostructure devices for low-temperature transport studies, with the advantage of gatability. This process utilizes electron beam lithography, photolithography, and wet etching techniques to laterally confine the two-dimensional electron gas, and possesses the unique feature that the metal etch mask for the electron beam defined narrow section is deposited directly on top of the heterostructure surface, allowing for use as a gate. Devices of lithographic widths from 0.4 to 2.0 μm have been successfully fabricated, where the 0.4 μm devices of both enhancement and depletion modes have been demonstrated to function down to 0.35 K in temperature.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.99170

    Articles: DFG German National Licenses
  19. 19
    Höpfel, R. A. ; Shah, J. ; Chang, T. Y. ; Sauer, N. J.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1987
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We introduce a new GaAs/AlxGa1−xAs single heterostructure, which allows local optical injection of a one-component confined plasma. The heterojunction is placed in the undoped region of a p-i-n structure, which provides a high built-in electric field for the separation of injected electrons and holes, as well as for the two-dimensional confinement of electrons. A time-of-flight measurement of the majority-electron drift velocity at room temperature is demonstrated.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.98532

    Articles: DFG German National Licenses
  20. 20
    Tell, B. ; Chang, T. Y. ; Brown-Goebeler, K. F. ; Kuo, J. M. ; Sauer, N. J.

    [S.l.] : American Institute of Physics (AIP)
    Published 1988
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The sheet resistance, Hall mobility, and carrier concentration as a function of He ion dose have been measured across the In1−x−yGaxAlyAs system. Starting with heavily doped n-type epitaxial layers (n∼1018 cm−3), except for the lowest band-gap constituent In0.53Ga0.47As, the sheet resistance can be increased more than five orders of magnitude for He doses above 2.5×1013 cm−2. For the other constituents, the sheet resistance can be made high enough and sufficiently thermally stable to be potentially useful for device applications.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.341520

    Articles: DFG German National Licenses