987 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 ƅ 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

    Near-field optical spectroscopy and microscopy of self-assembled GaNāˆ•AlN nanostructures

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    The spatial distribution and emission properties of small clusters of GaNquantum dots in an AlN matrix are studied using high-resolution electron and optical microscopy. High-resolution transmission electron microscopy reveals near vertical correlation among the GaNdots due to a sufficiently thin AlN spacer layer thickness, which allows strain induced stacking. Scanning electron and atomic force microscopy show lateral coupling due to a surface roughness of āˆ¼50ā€“60nm. Near-field photoluminescence in the illumination mode (both spatially and spectrally resolved) at 10K revealed emission from individual dots, which exhibits size distribution of GaNdots from localized sites in the stacked nanostructure. Strong spatial localization of the excitons is observed in GaNquantum dots formed at the tip of self-assembled hexagonal pyramid shapes with six [101ĀÆ1ĀÆ] facets

    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
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