The Experts below are selected from a list of 117714 Experts worldwide ranked by ideXlab platform
Yasushi Fujimoto - One of the best experts on this subject based on the ideXlab platform.
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properties of transparent ce yag ceramic phosphors for white led
Optical Materials, 2011Co-Authors: Shotaro Nishiura, Setsuhisa Tanabe, Kana Fujioka, Yasushi FujimotoAbstract:Abstract Transparent Ce:YAG ceramic phosphors were synthesized from the oxide powder which was produced by co-preparation method of the hydroxides. The Ce:YAG ceramics had a broad emission band peaked at 530 nm due to the 5d → 4f transition of Ce 3+ . The transmittances of the samples obtained were 70–87% at 800 nm. The absorption coefficient and emission intensity of Ce 3+ were increased with Increasing Thickness. Under 465 nm LED excitation, the color coordinates of the Ce:YAG ceramics shifted from the blue region to yellow region with Increasing sample Thickness, passing nearby the theoretical white point in the chromaticity diagram. The highest value of luminous efficacy of the ceramic white LED was 73.5 lm/W.
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properties of transparent ce yag ceramic phosphors for white led
Optical Materials, 2011Co-Authors: Shotaro Nishiura, Setsuhisa Tanabe, Kana Fujioka, Yasushi FujimotoAbstract:Abstract Transparent Ce:YAG ceramic phosphors were synthesized from the oxide powder which was produced by co-preparation method of the hydroxides. The Ce:YAG ceramics had a broad emission band peaked at 530 nm due to the 5d → 4f transition of Ce3+. The transmittances of the samples obtained were 70–87% at 800 nm. The absorption coefficient and emission intensity of Ce3+ were increased with Increasing Thickness. Under 465 nm LED excitation, the color coordinates of the Ce:YAG ceramics shifted from the blue region to yellow region with Increasing sample Thickness, passing nearby the theoretical white point in the chromaticity diagram. The highest value of luminous efficacy of the ceramic white LED was 73.5 lm/W.
Philippe Tailhades - One of the best experts on this subject based on the ideXlab platform.
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Influence of Thickness and microstructure on thermoelectric properties of Mg-doped CuCrO2 delafossite thin films deposited by RF-magnetron sputtering
Applied Surface Science, 2018Co-Authors: Inthuga Sinnarasa, Yohann Thimont, Lionel Presmanes, Corine Bonningue, Antoine Barnabé, Philippe TailhadesAbstract:Thermoelectric thin films are of great interest to microelectronic devices and miniaturized temperature sensors. In this article, we have studied the influence of film Thickness on the electrical and thermoelectric properties of Mg-doped CuCrO2 delafossite material (CuCrO2:Mg), a delafossite-type oxide. For this purpose, a serie of CuCr0.97Mg0.03O2 thin films with various Thicknesses (25, 50, 100, 200, 300, 400 and 600 nm) have been deposited by Radio Frequency (RF) magnetron sputtering. The as-deposited films were annealed at 550 °C under vacuum to obtain well crystallized delafossite phase. Grazing incidence X-ray diffraction patterns indicated that samples had pure delafossite structure. The atomic force microscope observations revealed the increase of the grain size with Increasing Thickness. The electrical and thermoelectric properties are characterized in temperature ranging from 40 to 220 °C and they were Thickness dependent. The Thickness dependency of the Seebeck coefficient was not expected and indicated that the carrier density changes with Thickness below 100 nm. The variation of the film resistivity below 100 nm Thickness was explained by both the change of the carrier density and the potential barrier addition due to small grain size. Using the electrical conductivity, the polaron activation energy (Eσp = 0.131 eV for 100 nm thick sample) was determined and its variation indicated that the stress/strain effect in the film with Increasing Thickness impacts the mobility. Moreover, the unexpected increase of the resistivity between 400 and 600 nm was also explained by the micro-cracks formation. The electrical and thermoelectric measurements showed a degenerated hopping semi-conductor behavior for the whole Thicknesses. The highest electrical conductivity (1.7 S·cm−1 at 40 °C) was obtained for 100 nm thick film which presented a Seebeck coefficient of +307 µV·K−1 at 40 °C. We report maximum power factor of 16 µW·m−1·K−2 at 40 °C for the optimum Thickness of 100 nm, which reached 59 µW·m−1·K−2 at 200 °C. The above results were explained in terms of microstructure and stress/strain effect.
Shotaro Nishiura - One of the best experts on this subject based on the ideXlab platform.
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properties of transparent ce yag ceramic phosphors for white led
Optical Materials, 2011Co-Authors: Shotaro Nishiura, Setsuhisa Tanabe, Kana Fujioka, Yasushi FujimotoAbstract:Abstract Transparent Ce:YAG ceramic phosphors were synthesized from the oxide powder which was produced by co-preparation method of the hydroxides. The Ce:YAG ceramics had a broad emission band peaked at 530 nm due to the 5d → 4f transition of Ce 3+ . The transmittances of the samples obtained were 70–87% at 800 nm. The absorption coefficient and emission intensity of Ce 3+ were increased with Increasing Thickness. Under 465 nm LED excitation, the color coordinates of the Ce:YAG ceramics shifted from the blue region to yellow region with Increasing sample Thickness, passing nearby the theoretical white point in the chromaticity diagram. The highest value of luminous efficacy of the ceramic white LED was 73.5 lm/W.
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properties of transparent ce yag ceramic phosphors for white led
Optical Materials, 2011Co-Authors: Shotaro Nishiura, Setsuhisa Tanabe, Kana Fujioka, Yasushi FujimotoAbstract:Abstract Transparent Ce:YAG ceramic phosphors were synthesized from the oxide powder which was produced by co-preparation method of the hydroxides. The Ce:YAG ceramics had a broad emission band peaked at 530 nm due to the 5d → 4f transition of Ce3+. The transmittances of the samples obtained were 70–87% at 800 nm. The absorption coefficient and emission intensity of Ce3+ were increased with Increasing Thickness. Under 465 nm LED excitation, the color coordinates of the Ce:YAG ceramics shifted from the blue region to yellow region with Increasing sample Thickness, passing nearby the theoretical white point in the chromaticity diagram. The highest value of luminous efficacy of the ceramic white LED was 73.5 lm/W.
Paul F Nealey - One of the best experts on this subject based on the ideXlab platform.
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defect annihilation in the directed self assembly of block copolymers in films with Increasing Thickness
Macromolecules, 2019Co-Authors: Xuanxuan Chen, Paulina Rincon Delgadillo, Zhang Jiang, Gordon S W Craig, Roel Gronheid, Paul F NealeyAbstract:We investigate directed self-assembly (DSA), with 3× density multiplication, of symmetric polystyrene-block-poly(methyl methacrylate) (L0 = 28 nm) with Increasing film Thicknesses and reveal a Thickness limit above which the defect annihilation mechanism is different than in thinner films. Block copolymer films of Increasing Thickness underwent DSA on a macroscopic chemical pattern under optimum geometrical and chemical conditions. Scanning electron microscopy and grazing-incidence small-angle X-ray scattering (GISAXS) were used to characterize the long-range ordering and buried structures as a function of film Thickness and thermal annealing time. Rotational GISAXS measurements revealed a critical Thickness of ∼3L0, below which defect annihilation is cooperative across the film depth and above which it is faster at the free surface than in the film’s interior. In the latter case, defects can persist in the film’s interior despite perfect assembly and registration at the free surface of the film.
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defect annihilation in the directed self assembly of block copolymers in films with Increasing Thickness
Macromolecules, 2019Co-Authors: Xuanxuan Chen, Paulina Rincon Delgadillo, Zhang Jiang, Gordon S W Craig, Roel Gronheid, Paul F NealeyAbstract:We investigate directed self-assembly (DSA), with 3× density multiplication, of symmetric polystyrene-block-poly(methyl methacrylate) (L0 = 28 nm) with Increasing film Thicknesses and reveal a thic...
S I Alekseev - One of the best experts on this subject based on the ideXlab platform.
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on the mechanism of microwave action on bilayer lipid membranes the role of the membrane forming hole in teflon film
Biophysics, 2009Co-Authors: S I Alekseev, M S Ziskin, Evgenevich Evgenij FesenkoAbstract:The distributions of specific absorption rate (SAR) and E-field in the membrane-forming hole of Teflon film and the surrounding electrolyte were calculated for 0.9 GHz microwave exposure. It was found that SAR in the hole increased greatly with Increasing Thickness of the Teflon film, Increasing electrolyte concentration, and decreasing diameter of the hole. The previously demonstrated significant changes in the conductivity of modified bilayer lipid membranes induced by microwave exposure can be explained by a local increase in SAR and subsequent elevation of temperature in the membrane-forming hole.
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effect of microwaves on bilayer lipid membranes role of a membrane forming hole in the teflon film
Biofizika, 2009Co-Authors: S I Alekseev, M S Ziskin, Evgenevich Evgenij FesenkoAbstract:The distributions of specific abcorption rate (SAR) and E-field in a membrane-forming hole of Teflon film and surrounding electrolyte were calculated for 0.9 GHz exposure. It was found that the specific absorption rate in the membrane-forming hole increased greatly with Increasing Thickness of the Teflon film, and electrolyte concentration and decreasing diameter of the hole. The previously demonstrated significant changes in the conductivity of modified bilayer lipid membranes induced by microwave exposure can be explained by a local increase in specific absorption rate and subsequent elevation of temperature in the membrane-forming hole of the Teflon film.
