The Experts below are selected from a list of 630 Experts worldwide ranked by ideXlab platform
Keiichi Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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photoluminescence from si nanocrystals dispersed in Phosphosilicate Glass thin films
Journal of Luminescence, 2000Co-Authors: Atsushi Mimura, Minoru Fujii, Shinji Hayashi, Keiichi YamamotoAbstract:Abstract Photoluminescence (PL) spectra of Si nanocrystals (nc-Si) in Phosphosilicate Glass matrices, and the PL decay dynamics were studied. The 1.4 eV peak corresponding to the recombination of electron–hole pairs confined in nc-Si (band-edge PL) became intense with increasing the P concentration in the matrix region, while the 0.9 eV peak related to the defects at the interfaces between nc-Si and matrices became weaker. The lifetime of the band-edge PL increased with the P concentration. These results indicate that the improvement of the band-edge PL efficiency is achieved by decreasing the interface defect density by P doping.
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single electron tunneling through si nanocrystals dispersed in Phosphosilicate Glass thin films
Physica E-low-dimensional Systems & Nanostructures, 2000Co-Authors: Yoku Inoue, Minoru Fujii, Shinji Hayashi, Atsushi Tanaka, Keiichi YamamotoAbstract:Electrical transport properties of extremely thin Phosphosilicate Glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post-annealing. Periodic Coulomb staircases were clearly observed in the DC current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.
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single electron tunneling through si nanocrystals dispersed in Phosphosilicate Glass thin films
Journal of Applied Physics, 1999Co-Authors: Yoku Inoue, Minoru Fujii, Shinji Hayashi, Atsushi Tanaka, Keiichi YamamotoAbstract:Electrical transport properties of extremely thin Phosphosilicate Glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post annealing. Periodic Coulomb staircases were clearly observed in the dc current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing the temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.
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photoluminescence from si nanocrystals dispersed in Phosphosilicate Glass thin films improvement of photoluminescence efficiency
Applied Physics Letters, 1999Co-Authors: Minoru Fujii, Atsushi Mimura, Shinji Hayashi, Keiichi YamamotoAbstract:Photoluminescence (PL) from Si nanocrystals (nc-Si) dispersed in Phosphosilicate Glass thin films was studied. It was found that, at room temperature, the 1.4 eV PL due to the recombination of electron-hole pairs in nc-Si becomes intense as the P concentration increases. At low temperatures, an additional peak related to defects at interfaces between nc-Si and the matrix was observed at about 0.9 eV. In contrast to the 1.4 eV peak, the 0.9 eV peak became weaker with increasing P concentration and almost disappeared at a P concentration of 1.5 mol %. These results suggest that the number of interface defects decreases with increasing P concentration and that this decrease leads to an improvement of the band-edge PL of nc-Si.
Minoru Fujii - One of the best experts on this subject based on the ideXlab platform.
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atom probe tomography analysis of boron and or phosphorus distribution in doped silicon nanocrystals
Journal of Physical Chemistry C, 2016Co-Authors: Keita Nomoto, Hiroshi Sugimoto, Andrew J Breen, Anna V Ceguerra, Takashi Kanno, Simon P Ringer, Ivan Perez Wurfl, Gavin Conibeer, Minoru FujiiAbstract:Silicon nanocrystals (Si NCs) are intensively studied for optoelectronic and biological applications due to having highly attractive features such as band engineering. Although doping is often used to control the optical and electrical properties, the related structural properties of solely doped and codoped Si NCs are not well-understood. In this study, we report the boron (B) and/or phosphorus (P) distribution in Si NCs embedded in borosilicate Glass (BSG), Phosphosilicate Glass (PSG), and boroPhosphosilicate Glass (BPSG) using atom probe tomography (APT). We compared solely and codoped Si NCs grown at different temperatures so that we may compare the effects of codoping and temperature on the B and/or P distribution. Proximity histograms and cluster analyses reveal that there exist boron-rich layers surrounding Si NCs and also B–P clusters within the Si NCs. Raman spectra also show a structural change between codoped Si NCs in solids and free-standing codoped Si NCs. These results lead us to understand...
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nonlinear optical properties of phosphorous doped si nanocrystals embedded in Phosphosilicate Glass thin films
Optics Express, 2009Co-Authors: Kenji Imakita, Minoru Fujii, Masahiko Ito, Shinji HayashiAbstract:Nonlinear optical properties of phosphorus (P) -doped silicon (Si) nanocrystals are studied by z-scan technique in femtosecond regime at around 1.6 eV. The nonlinear refractive index (n2) and nonlinear absorption coefficient (β) of Si-ncs are significantly enhanced by P-doping. The enhancement of n2 is accompanied by the increase of the linear absorption in the same energy region, suggesting that impurity-related energy states are responsible for the enhancement of the nonlinear optical response.
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photoluminescence from si nanocrystals dispersed in Phosphosilicate Glass thin films
Journal of Luminescence, 2000Co-Authors: Atsushi Mimura, Minoru Fujii, Shinji Hayashi, Keiichi YamamotoAbstract:Abstract Photoluminescence (PL) spectra of Si nanocrystals (nc-Si) in Phosphosilicate Glass matrices, and the PL decay dynamics were studied. The 1.4 eV peak corresponding to the recombination of electron–hole pairs confined in nc-Si (band-edge PL) became intense with increasing the P concentration in the matrix region, while the 0.9 eV peak related to the defects at the interfaces between nc-Si and matrices became weaker. The lifetime of the band-edge PL increased with the P concentration. These results indicate that the improvement of the band-edge PL efficiency is achieved by decreasing the interface defect density by P doping.
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single electron tunneling through si nanocrystals dispersed in Phosphosilicate Glass thin films
Physica E-low-dimensional Systems & Nanostructures, 2000Co-Authors: Yoku Inoue, Minoru Fujii, Shinji Hayashi, Atsushi Tanaka, Keiichi YamamotoAbstract:Electrical transport properties of extremely thin Phosphosilicate Glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post-annealing. Periodic Coulomb staircases were clearly observed in the DC current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.
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single electron tunneling through si nanocrystals dispersed in Phosphosilicate Glass thin films
Journal of Applied Physics, 1999Co-Authors: Yoku Inoue, Minoru Fujii, Shinji Hayashi, Atsushi Tanaka, Keiichi YamamotoAbstract:Electrical transport properties of extremely thin Phosphosilicate Glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post annealing. Periodic Coulomb staircases were clearly observed in the dc current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing the temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.
Shinji Hayashi - One of the best experts on this subject based on the ideXlab platform.
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nonlinear optical properties of phosphorous doped si nanocrystals embedded in Phosphosilicate Glass thin films
Optics Express, 2009Co-Authors: Kenji Imakita, Minoru Fujii, Masahiko Ito, Shinji HayashiAbstract:Nonlinear optical properties of phosphorus (P) -doped silicon (Si) nanocrystals are studied by z-scan technique in femtosecond regime at around 1.6 eV. The nonlinear refractive index (n2) and nonlinear absorption coefficient (β) of Si-ncs are significantly enhanced by P-doping. The enhancement of n2 is accompanied by the increase of the linear absorption in the same energy region, suggesting that impurity-related energy states are responsible for the enhancement of the nonlinear optical response.
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photoluminescence from si nanocrystals dispersed in Phosphosilicate Glass thin films
Journal of Luminescence, 2000Co-Authors: Atsushi Mimura, Minoru Fujii, Shinji Hayashi, Keiichi YamamotoAbstract:Abstract Photoluminescence (PL) spectra of Si nanocrystals (nc-Si) in Phosphosilicate Glass matrices, and the PL decay dynamics were studied. The 1.4 eV peak corresponding to the recombination of electron–hole pairs confined in nc-Si (band-edge PL) became intense with increasing the P concentration in the matrix region, while the 0.9 eV peak related to the defects at the interfaces between nc-Si and matrices became weaker. The lifetime of the band-edge PL increased with the P concentration. These results indicate that the improvement of the band-edge PL efficiency is achieved by decreasing the interface defect density by P doping.
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single electron tunneling through si nanocrystals dispersed in Phosphosilicate Glass thin films
Physica E-low-dimensional Systems & Nanostructures, 2000Co-Authors: Yoku Inoue, Minoru Fujii, Shinji Hayashi, Atsushi Tanaka, Keiichi YamamotoAbstract:Electrical transport properties of extremely thin Phosphosilicate Glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post-annealing. Periodic Coulomb staircases were clearly observed in the DC current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.
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single electron tunneling through si nanocrystals dispersed in Phosphosilicate Glass thin films
Journal of Applied Physics, 1999Co-Authors: Yoku Inoue, Minoru Fujii, Shinji Hayashi, Atsushi Tanaka, Keiichi YamamotoAbstract:Electrical transport properties of extremely thin Phosphosilicate Glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post annealing. Periodic Coulomb staircases were clearly observed in the dc current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing the temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.
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photoluminescence from si nanocrystals dispersed in Phosphosilicate Glass thin films improvement of photoluminescence efficiency
Applied Physics Letters, 1999Co-Authors: Minoru Fujii, Atsushi Mimura, Shinji Hayashi, Keiichi YamamotoAbstract:Photoluminescence (PL) from Si nanocrystals (nc-Si) dispersed in Phosphosilicate Glass thin films was studied. It was found that, at room temperature, the 1.4 eV PL due to the recombination of electron-hole pairs in nc-Si becomes intense as the P concentration increases. At low temperatures, an additional peak related to defects at interfaces between nc-Si and the matrix was observed at about 0.9 eV. In contrast to the 1.4 eV peak, the 0.9 eV peak became weaker with increasing P concentration and almost disappeared at a P concentration of 1.5 mol %. These results suggest that the number of interface defects decreases with increasing P concentration and that this decrease leads to an improvement of the band-edge PL of nc-Si.
Evgeny M. Dianov - One of the best experts on this subject based on the ideXlab platform.
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luminescence properties of ir emitting bismuth centres in sio2 based Glasses in the uv to near ir spectral region
Quantum Electronics, 2015Co-Authors: E G Firstova, I A Bufetov, V F Khopin, V V Velmiskin, S V Firstov, G A Bufetova, K N Nishchev, A N Guryanov, Evgeny M. DianovAbstract:We have studied UV excitation spectra of IR luminescence in bismuth-doped Glasses of various compositions and obtained energy level diagrams of IR-emitting bismuth-related active centres (BACs) associated with silicon and germanium atoms up to ~5.2 eV over the ground level. A possible energy level diagram of the BACs in Phosphosilicate Glass has been proposed. The UV excitation peaks for the IR luminescence of the BACs in the Glasses have been shown to considerably overlap with absorption bands of the Bi3+ ion, suggesting that Bi3+ may participate in BAC formation.
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Hydroxyl groups in Phosphosilicate Glass for optical fibers
Inorganic Materials, 2000Co-Authors: Victor G. Plotnichenko, V. O. Sokolov, E. B. Kryukova, Evgeny M. DianovAbstract:To gain insight into the local environment of impurity hydroxyl groups in Phosphosilicate Glass and determine its signatures in the vibration spectrum, the IR absorption spectra of Phosphosilicate Glasses containing up to 20 mol % P2O5 were analyzed. The interaction of hydroxyl groups with phosphorus-containing centers was studied with the use of a cluster model and the PM3 and MNDO quantum-chemical methods. The observed changes in the OH-stretching region of the absorption spectrum were interpreted using the modeling results.
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UV irradiation-induced structural transformation in Phosphosilicate Glass
Journal of Non-Crystalline Solids, 1999Co-Authors: Evgeny M. Dianov, V. V. Koltashev, Victor G. Plotnichenko, V. O. Sokolov, Vladimir B. SulimovAbstract:Raman spectra of optical fibers with core of P2O5-SiO2 Glass with P2O5 concentrations about 4, 9 and 12 mol%, manufactured using modified chemical vapor deposition (MCVD) technology were investigated. Significant changes of the spectra were observed after UV irradiation by KrF excimer laser (244 nm, 1 kJ cm-2). An interpretation of the photostructural changes is proposed based on quantum chemical calculation of phosphorus-related centers.
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uv irradiation induced structural transformation in Phosphosilicate Glass fiber
Optics Letters, 1998Co-Authors: V G Plotnichenko, V. V. Koltashev, V. O. Sokolov, Vladimir B. Sulimov, Evgeny M. DianovAbstract:The Raman spectra of Phosphosilicate core P2O5–SiO2 fibers were investigated. Significant changes in the spectra were observed after UV irradiation of the fibers. An interpretation of the photostructural changes confirmed by computer simulation of phosphorus-related centers is proposed.
V G Plotnichenko - One of the best experts on this subject based on the ideXlab platform.
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on the mechanism of photoinduced refractive index changes in Phosphosilicate Glass
Quantum Electronics, 2010Co-Authors: Yu V Larionov, V. O. Sokolov, V G PlotnichenkoAbstract:The photoinduced growth of the refractive index of Phosphosilicate Glass during Bragg grating inscription and the thermal decay of the grating have a number of unusual features. The observed index variations are interpreted in terms of a new model for photoinduced Glass network rearrangement. The model assumes the formation of photoinduced voids (nanopores) in the Glass network near point defects. The nanopores may migrate through the network via bond switching when the network is in a 'soft' state. The photoinduced variations in network density lead to index variations.
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rearrangement of a Phosphosilicate Glass network induced by the 193 nm radiation
Quantum Electronics, 2008Co-Authors: Yu V Larionov, V. O. Sokolov, V G PlotnichenkoAbstract:The IR absorption and Raman spectra of Phosphosilicate Glass (PSG) are measured during its exposure to radiation at a wavelength of 193 nm. The obtained data demonstrate the complicated rearrangement dynamics of the Glass network around phosphor atoms and of the Glass network as a whole. The experimental dependences are explained by the model of the PSG network based on the concepts of the theory of rigidity percolation.
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defects of a Phosphosilicate Glass exposed to the 193 nm radiation
Quantum Electronics, 2007Co-Authors: Yu V Larionov, V. O. Sokolov, V G PlotnichenkoAbstract:Induced absorption is measured in a hydrogen-unloaded Phosphosilicate Glass (PSG) in spectral ranges from 140 to 850 nm and from 1000 to 1700 nm before and after its exposure to the 193-nm radiation. It is shown that the induced-absorption bands in the range between 140 and 300 nm do not coincide with the bands observed earlier after exposing a PSG to X-rays. It is assumed that the photorefractive effect in the PSG is related to variations induced in the Glass network rather than to defects responsible for the induced-absorption bands.
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uv irradiation induced structural transformation in Phosphosilicate Glass fiber
Optics Letters, 1998Co-Authors: V G Plotnichenko, V. V. Koltashev, V. O. Sokolov, Vladimir B. Sulimov, Evgeny M. DianovAbstract:The Raman spectra of Phosphosilicate core P2O5–SiO2 fibers were investigated. Significant changes in the spectra were observed after UV irradiation of the fibers. An interpretation of the photostructural changes confirmed by computer simulation of phosphorus-related centers is proposed.
