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Your search keyword '"Chow, P."' showing total 113 results
Start Over Author "Chow, P." Journal applied physics letters
113 results on '"Chow, P."'

1. Steady-state junction current distribution in p-n GaN diodes measured using low-energy electron microscopy (LEEM)

Author

Ho, Wan Ying, Johnson, Cameron W, Tak, Tanay, Sauty, Mylène, Chow, Yi Chao, Nakamura, Shuji, Schmid, Andreas, Peretti, Jacques, Weisbuch, Claude, and Speck, James S

Subjects
Physical Sciences, Condensed Matter Physics, Engineering, Technology, Applied Physics, Physical sciences
Abstract

We report on the measurement of the lateral distribution of the junction current of an electrical biased p-n GaN diode by electron emission microscopy using a low-energy electron microscope. The vacuum level at the surface of the diode was lowered by deposition of cesium to achieve negative electron affinity, allowing overflow electrons at the surface of the biased diodes to be emitted and their spatial distribution imaged. The results were compared to the literature, and a good match with analytical solutions by Joyce and Wemple [J. Appl. Phys. 41, 3818 (1970)] was obtained.

Published
2023

2. Growth of large, defect-free pure C60 single crystals

Author

Meng, R. L, Ramirez, D, Jiang, X, Chow, P. C, Diaz, C, Matsuishi, K, Moss, S. C, Hor, P. H, and Chu, C. W

Subjects
Solid-State Physics
Abstract

Millimeter-sized single crystals of C60 were grown by sublimation of C60 powder in a vacuum for 6-24 h. The crystals had excellent facets, were free of C70 or solvent, and showed face-centered cubic symmetry with a very small mosaic spread down to 0.01 deg.

Published
1991
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11. Electron irradiation of AlGaN∕GaN and AlN∕GaN heterojunctions

Author

Polyakov, A. Y., primary, Smirnov, N. B., additional, Govorkov, A. V., additional, Markov, A. V., additional, Pearton, S. J., additional, Dabiran, A. M., additional, Wowchak, A. M., additional, Cui, B., additional, Osinsky, A. V., additional, Chow, P. P., additional, Kolin, N. G., additional, Boiko, V. M., additional, and Merkurisov, D. I., additional

Published
2008
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30. dc and rf performance of proton-irradiated AlGaN/GaN high electron mobility transistors

Author

Luo, B., primary, Johnson, J. W., additional, Ren, F., additional, Allums, K. K., additional, Abernathy, C. R., additional, Pearton, S. J., additional, Dwivedi, R., additional, Fogarty, T. N., additional, Wilkins, R., additional, Dabiran, A. M., additional, Wowchack, A. M., additional, Polley, C. J., additional, Chow, P. P., additional, and Baca, A. G., additional

Published
2001
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37. Detection of an endocrine disrupter biomarker, vitellogenin, in largemouth bass serum using AlGaN/GaN high electron mobility transistors.

Author

Byung Hwan Chu, Chang, C. Y., Kroll, Kevin, Denslow, Nancy, Yu-Lin Wang, Pearton, S. J., Dabiran, A. M., Wowchak, A. M., Cui, B., Chow, P. P., and Fan Ren

Subjects
FREE electron theory of metals, LARGEMOUTH bass, MODULATION-doped field-effect transistors, PROTEIN precursors, VITELLOGENINS, ELECTRON gas
Abstract

Endocrine disrupters are known to have negative effects on the environment and human health. Real time detection of vitellogenin, an endocrine disrupter biomarker, was demonstrated using AlGaN/GaN high electron mobility transistors (HEMTs). Anti-vitellogenin antibodies were chemically anchored to the gold-coated gate area of the HEMT and immobilized with thioglycolic acid. The potential difference that occurs from the vitellogenin antigen-antibody interaction-induced caused a drain current change in the HEMT. The HEMT sensor was tested for vitellogenin detection both in phosphate buffer saline and largemouth bass serum. [ABSTRACT FROM AUTHOR]

Published
2010
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38. Measurement of Zn0.95Cd0.05O/ZnO (0001) heterojunction band offsets by x-ray photoelectron spectroscopy.

Author

Jau-Jiun Chen, Ren, F., Yuanjie Li, Norton, D. P., Pearton, S. J., Osinsky, A., Dong, J. W., Chow, P. P., and Weaver, J. F.

Subjects
X-rays, PHOTOELECTRONS, SPECTRUM analysis, FORCE & energy, CONDUCTION electrons, MOLECULAR beams
Abstract

X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band (ΔEv) of Zn0.95Cd0.05O/ZnO heterostructures grown by rf plasma-enhanced molecular-beam epitaxy. A value of ΔEv=0.17±0.03 eV was obtained by using the Zn 2p energy level as a reference. Given the experimental band gap of 2.9 eV for the Zn0.95Cd0.05O, this would indicate a conduction band offset ΔEC of 0.30 eV in this system. [ABSTRACT FROM AUTHOR]

Published
2005
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39. Minority carrier transport in p-type Zn0.9Mg0.1O doped with phosphorus.

Author

Lopatiuk, O., Burdett, W., Chernyak, L., Ip, K. P., Heo, Y. W., Norton, D. P., Pearton, S. J., Hertog, B., Chow, P. P., and Osinsky, A.

Subjects
ZINC, PHOSPHORUS, IRRADIATION, CATHODOLUMINESCENCE, ELECTRON beams, ELECTRON optics
Abstract

Minority carrier diffusion length and lifetime in p-Zn0.9Mg0.1O doped with phosphorus were obtained from local electron beam irradiation measurements. The irradiation resulted in an increase of up to 25% in minority electron diffusion length from the initial value of ∼2.12 μm and in a simultaneous decrease of the peak near-bandedge cathodoluminescence intensity. The observed phenomena are attributed to charging of phosphorus-related deep acceptor level(s), which is consistent with the activation energy of 256±20 meV found for the effect of electron injection in Zn0.9Mg0.1O. [ABSTRACT FROM AUTHOR]

Published
2005
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40. MgZnO/AlGaN heterostructure light-emitting diodes.

Author

Osinsky, A., Dong, J. W., Kauser, M. Z., Hertog, B., Dabiran, A. M., Chow, P. P., Pearton, S. J., Lopatiuk, O., and Chernyak, L.

Subjects
HETEROSTRUCTURES, LIGHT emitting diodes, PIEZOELECTRICITY, POLARIZATION (Nuclear physics), MAGNESIUM, ZINC oxide, ALUMINUM, GALLIUM nitride
Abstract

We report on p–n junction light-emitting diodes fabricated from MgZnO/ZnO/AlGaN/GaN triple heterostructures. Energy band diagrams of the light-emitting diode structure incorporating piezoelectric and spontaneous polarization fields were simulated, revealing a strong hole confinement near the n-ZnO/p-AlGaN interface with a hole sheet density as large as 1.82×1013 cm-2 for strained structures. The measured current–voltage (IV) characteristics of the triple heterostructure p–n junctions have rectifying characteristics with a turn-on voltage of ∼3.2 V. Electron-beam-induced current measurements confirmed the presence of a p–n junction located at the n-ZnO/p-AlGaN interface. Strong optical emission was observed at ∼390 nm as expected for excitonic optical transitions in these structures. Experimental spectral dependence of the photocurrent confirmed the excitonic origin of the optical transition at 390 nm. Light emission was measured up to 650 K, providing additional confirmation of the excitonic nature of the optical transitions in the devices. [ABSTRACT FROM AUTHOR]

Published
2004
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41. Influence of [sup 60]Co γ-rays on dc performance of AlGaN/GaN high electron mobility transistors.

Author

Luo, B., Johnson, J. W., Ren, F., Allums, K. K., Abernathy, C. R., Pearton, S. J., Dabiran, A. M., Wowchack, A. M., Polley, C. J., Chow, P. P., Schoenfeld, D., and Baca, A. G.

Subjects
GALLIUM nitride, ALUMINUM, ELECTRON mobility, TRANSISTORS, THERMAL properties
Abstract

AlGaN/GaN high electron mobility transistors (HEMTs) with different gate length and widths were irradiated with [sup 60]Co γ-rays to doses up to 600 Mrad. Little measurable change in dc performance of the devices was observed for doses lower than 300 Mrad. At the maximum dose employed, the forward gate current was significantly decreased, with an accompanying increase in reverse breakdown voltage. This is consistent with a decrease in effective carrier density in the channel as a result of the introduction of deep electron trapping states. The threshold voltage shifted to more negative voltages as a result of the irradiation, while the magnitude of the drain–source current was relatively unaffected. This is consistent with a strong increase of trap density in the material. The magnitude of the decrease in transconductance of the AlGaN/GaN HEMTs is roughly comparable to the decrease in dc current gain observed in InGaP/GaAs heterojunction bipolar transistors irradiated under similar conditions. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2002
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43. Study of high electrical field induced degradation of channel response in metal-oxide-semiconductor field-effect transistors using an ac conductance technique.

Author

Chow, P. D. and Wang, K. L.

Subjects
*METAL oxide semiconductor field-effect transistors, *ELECTRIC fields
Abstract

ac conductance (G) measurements in the frequency domain are used to monitor the degradation of the inversion layer response in metal-oxide-semiconductor field-effect transistors (MOSFET’s) due to high field stressing. The admittance of the conduction channel of the MOSFET’s is analyzed by use of a transmission line model. The time constant which governs the frequency response of the MOSFET inverted channel is extracted from the peak of the G/ω vs ω curve and is shown to be an important and sensitive parameter for studying the degradation of MOSFET interface properties after high field stressing. Measured data on 9 and 35 nm gate oxide MOSFET’s showed that the channel response degradation by high field stressing depends strongly on the gate oxide thickness. [ABSTRACT FROM AUTHOR]

Published
1985
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44. Dependence of critical thickness on growth temperature in GexSi1-x/Si superlattices.

Author

Miles, R. H., McGill, T. C., Chow, P. P., Johnson, D. C., Hauenstein, R. J., Nieh, C. W., and Strathman, M. D.

Subjects
SUPERLATTICES, EPITAXY, GERMANIUM compounds, SILICON compounds
Abstract

We present direct evidence for the dependence of critical thickness on growth temperature in a lattice-mismatched epitaxial system. Ge0.5Si0.5/Si strained-layer superlattices have been grown by molecular beam epitaxy on (100) Si substrates at temperatures between 330 and 530 °C. The extent to which lattice mismatch is accommodated by elastic strain has been determined through x-ray diffraction, channeled Rutherford backscattering spectroscopy, and transmission electron microscopy. Lattice mismatch is found to be accommodated purely elastically in a structure grown at 365 °C. Samples grown at higher temperatures are seen to display increasingly high densities of misfit-accommodating dislocations. This growth-temperature dependence may account for apparent inconsistencies in critical thickness data reported in the literature. Our results clearly demonstrate the need to account adequately for the kinetics of defect formation in the prediction of critical thicknesses. [ABSTRACT FROM AUTHOR]

Published
1988
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45. Infrared photoluminescence spectra from HgTe-CdTe superlattices.

Author

Hetzler, S. R., Baukus, J. P., Hunter, A. T., Faurie, J. P., Chow, P. P., and McGill, T. C.

Subjects
PHOTOLUMINESCENCE, SUPERLATTICES, INFRARED technology
Abstract

We report the first observation of infrared photoluminescence from HgTe-CdTe superlattices. A superlattice grown to have layers of HgTe 38-40 Å thick and layers of CdTe 18-20 Å thick is found to show a peak in the 140-K spectra at 105 meV (11.8 µm). A second superlattice grown to have HgTe layers 50 Å thick and CdTe layers 50 Å thick is found to show a peak at 205 meV (6.0 µm) at 170 K. In both cases, the energy of the luminescence is significantly lower than that for HgCdTe alloys with the same average composition as each sample. [ABSTRACT FROM AUTHOR]

Published
1985
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