106 research outputs found

    Dressed Photon-phonon Technology for Ultra Flat Surface

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    A reduction of the surface roughness, Ra, is required in various applications including electronic devic-es and / or optical devices. Although chemical-mechanical polishing (CMP) has been used to flatten the sur-faces, it is generally limited to reducing Ra to about 2 Å because the polishing pad roughness is as large as 10 m, and the polishing-particle diameters in the slurry are as large as 100 nm. We therefore developed a new polishing method, dressed-photon and phonon etching (DPP etching), that uses dressed photon based on an autonomous phonon-assisted process. DPP etching does not use any polishing pad, with which we obtained ultra-flat silica surface with angstrom-scale average roughness as small as Ra of 0.1 nm. Addi-tionally, we succeeded in reduction of the Ra for the three-dimensional structures. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3526

    Evaluation of the discrete energy levels of individual ZnO nanorod single-quantum-well structures using near-field ultraviolet photoluminescence spectroscopy

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    Spatially and spectrally resolved photoluminescence imaging of individual ZnO/ZnMgO nanorod single-quantum-well structures (SQWs) with a spatial resolution of 55 nm was performed using the optical near-field technique with a metallized UV fiber probe. Using excitation power density-dependent photoluminescence spectra of a ZnO/ZnMgO SQW nanorod, we observed the discrete energy levels in a ZnO quantum-well layer. (C) 2004 American Institute of Physics.open112930sciescopu

    Near-field measurement of spectral anisotropy and optical absorption of isolated ZnO nanorod single-quantum-well structures

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    We report low-temperature near-field spectroscopy of isolated ZnO/ZnMgO single-quantum-well structures (SQWs) on the end of ZnO nanorod to define their potential for nanophotonics. First, absorption spectra of isolated ZnO/ZnMgO nanorod SQWs with the Stokes shift as small as 3 meV and very sharp photoluminescent peaks indicate that the nanorod SQWs are of very high optical quality. Furthermore, we performed polarization spectroscopy of isolated ZnO SQWs, and observed valence-band anisotropy of ZnO SQWs in photoluminescence spectra directly. Since the exciton in a quantum structure is an ideal two-level system with long coherence times, our results provide criteria for designing nanophotonic devices. (c) 2005 American Institute of Physics.open111828sciescopu

    Nanophotonic switch using ZnO nanorod double-quantum-well structures

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    The authors report on time-resolved near-field spectroscopy of ZnO/ZnMgO nanorod double-quantum-well structures (DQWs) for a nanometer-scale photonic device. They observed nutation of the population between the resonantly coupled exciton states of DQWs. Furthermore, they demonstrated switching dynamics by controlling the exciton excitation in the dipole-inactive state via an optical near field. The results of time-resolved near-field spectroscopy of isolated DQWs described here are a promising step toward designing a nanometer-scale photonic switch and related devices. (C) 2007 American Institute of Physics.open116881sciescopu

    Quantum confinement effect in ZnO/Mg0.2Zn0.8O multishell nanorod heterostructures

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    We report on photoluminescence measurements of Mg0.2Zn0.8O/ZnO/Mg0.2Zn0.8O multishell layers on ZnO core nanorods. Dominant excitonic emissions in the photoluminescence spectra show a blueshift depending on the ZnO shell layer thickness attributed to the quantum confinement effect in the nanorod heterostructure radial direction. Furthermore, near-field scanning optical microscopy clearly shows sharp photoluminescence peaks from the individual nanorod quantum structures, corresponding to subband levels.open114747sciescopu

    Evaluation of the discrete energy levels of individual ZnO nanaorod single-quantum-well structures using near-field ultraviolet photoluminescence spectroscopy

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    Spatially and spectrally resolved photoluminescence imaging of individual ZnO/ZnMgO nanorod single-quantum-well structures (SQWs) with a spatial resolution of 55 nm was performed using the optical near-field technique with a metallized UV fiber probe. Using excitation power density-dependent photoluminescence spectra of a ZnO/ZnMgO SQW nanorod, we observed the discrete energy levels in a ZnO quantum-well layer. (C) 2004 American Institute of Physics.Research by S.J.A. and G.C.Y. was supported by Korea Research Foundation Grant No. KRF-2002-041-C00098

    Influence of the high-power ion-beam irradiation of a hydroxyapatite target on the properties of formed calcium phosphate coatings

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    The physical-mechanical of properties of biocompatible calcium phosphate coatings deposited onto titanium and silicon substrates from erosion materials, which are generated by irradiating hydroxyapatite (synthetic and natural) targets by means of the high-power pulsed ion beam of a Temp-4 accelerator, are investigated. A calculation technique for predicting the rate and energy efficiency of deposition using pulsed ion beams is proposed. Their characteristics are analyzed as applied to the formation of calcium phosphate coatings
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