The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Athos Petrou - One of the best experts on this subject based on the ideXlab platform.
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Reduction of spin Injection Efficiency by interface defect spin scattering in ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes.
Physical review letters, 2002Co-Authors: Rhonda M. Stroud, Aubrey T. Hanbicki, Yun Daniel Park, George Kioseoglou, A. G. Petukhov, B. T. Jonker, Grigorios Itskos, Athos PetrouAbstract:We report the first experimental demonstration that interface microstructure limits diffusive electrical spin-Injection Efficiency across heteroepitaxial interfaces. An inverse correlation be-tween spin-polarized electron Injection Efficiency and interface defect density is demonstrated for ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes that exhibit quantum well spin polarizations up to 85%. A theoretical treatment shows that the suppression of spin Injection due to interface defects results from the contribution of the defect potential to the spin-orbit interaction, which increases the spin-flip scattering.
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reduction of spin Injection Efficiency by interface defect spin scattering in znmnse algaas gaas spin polarized light emitting diodes
Physical Review Letters, 2002Co-Authors: Rhonda M. Stroud, Aubrey T. Hanbicki, Yun Daniel Park, George Kioseoglou, A. G. Petukhov, B. T. Jonker, Grigorios Itskos, Athos PetrouAbstract:We report the first experimental demonstration that interface microstructure limits diffusive electrical spin-Injection Efficiency across heteroepitaxial interfaces. An inverse correlation be-tween spin-polarized electron Injection Efficiency and interface defect density is demonstrated for ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes that exhibit quantum well spin polarizations up to 85%. A theoretical treatment shows that the suppression of spin Injection due to interface defects results from the contribution of the defect potential to the spin-orbit interaction, which increases the spin-flip scattering.
Rhonda M. Stroud - One of the best experts on this subject based on the ideXlab platform.
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Reduction of spin Injection Efficiency by interface defect spin scattering in ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes.
Physical review letters, 2002Co-Authors: Rhonda M. Stroud, Aubrey T. Hanbicki, Yun Daniel Park, George Kioseoglou, A. G. Petukhov, B. T. Jonker, Grigorios Itskos, Athos PetrouAbstract:We report the first experimental demonstration that interface microstructure limits diffusive electrical spin-Injection Efficiency across heteroepitaxial interfaces. An inverse correlation be-tween spin-polarized electron Injection Efficiency and interface defect density is demonstrated for ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes that exhibit quantum well spin polarizations up to 85%. A theoretical treatment shows that the suppression of spin Injection due to interface defects results from the contribution of the defect potential to the spin-orbit interaction, which increases the spin-flip scattering.
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reduction of spin Injection Efficiency by interface defect spin scattering in znmnse algaas gaas spin polarized light emitting diodes
Physical Review Letters, 2002Co-Authors: Rhonda M. Stroud, Aubrey T. Hanbicki, Yun Daniel Park, George Kioseoglou, A. G. Petukhov, B. T. Jonker, Grigorios Itskos, Athos PetrouAbstract:We report the first experimental demonstration that interface microstructure limits diffusive electrical spin-Injection Efficiency across heteroepitaxial interfaces. An inverse correlation be-tween spin-polarized electron Injection Efficiency and interface defect density is demonstrated for ZnMnSe/AlGaAs-GaAs spin-polarized light-emitting diodes that exhibit quantum well spin polarizations up to 85%. A theoretical treatment shows that the suppression of spin Injection due to interface defects results from the contribution of the defect potential to the spin-orbit interaction, which increases the spin-flip scattering.
Ryuzi Katoh - One of the best experts on this subject based on the ideXlab platform.
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Electron Injection Efficiency in dye-sensitized solar cells
Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2014Co-Authors: Ryuzi Katoh, Akihiro FurubeAbstract:Abstract Electron Injection processes in dye-sensitized solar cells (DSCs), which involve electron transfer from an excited dye to a semiconductor nanoparticle, have been discussed in many previously reported studies. In this review we discuss the working principles and primary processes of DSCs, as well as these processes’ influence on basic properties of solar cells such as open-circuit voltage, short-circuit current, and incident photon-to-current conversion Efficiency (IPCE). We focus our attention on the electron Injection process, and we introduce methods to determine electron Injection Efficiency ( Φ inj ) using time-resolved fluorescence and absorption spectroscopy techniques. We present difficulties associated with obtaining Φ inj by means of such techniques, and we propose nanosecond time-resolved transient absorption spectroscopy as a reliable method. Then, Φ inj values obtained are summarized. Factors limiting Φ inj are discussed from the perspective of free energy changes for electron Injection, the molecular structure of sensitizer dyes on the surface, and the presence of fast charge recombination pathways.
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Effect of dye coverage on photo-induced electron Injection Efficiency in N719-sensitized nanocrystalline TiO2 films
Chemical Physics Letters, 2010Co-Authors: Ryuzi Katoh, Akihiro Furube, Nobuhiro Fuke, Naoki KoideAbstract:The effect of dye coverage on the photo-induced electron Injection Efficiency in N719-sensitized nanocrystalline TiO2 films was studied by transient absorption spectroscopy. We evaluated the electron Injection Efficiency of films with several dye concentrations on the surface and found no significant difference between them. We also studied the suppression of the Efficiency by the addition of tBP (4-tert-butylpyridine) and found that the effect of tBP was more pronounced for films with lower dye loading. This suggests that sensitizer dyes adsorbed densely onto the surface suppress the adsorption of tBP.
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Quantitative study of solvent effects on electron Injection Efficiency for black-dye-sensitized nanocrystalline TiO2 films
Solar Energy Materials and Solar Cells, 2009Co-Authors: Ryuzi Katoh, Motohiro Kasuya, Akihiro Furube, Nobuhiro Fuke, Naoki Koide, Liyuan HanAbstract:The effects of various solvents on the electron Injection Efficiency for nanocrystalline TiO 2 films sensitized with the black dye trithiocyanato(4,4',4"-tricarboxy-2,2':6',2"-terpyridine)ruthenium(II) (Ru(tcterpy)(NCS) 3 ) have been studied quantitatively. The electron Injection Efficiency for the film dried in air was estimated as 0.4 using a time-resolved microwave conductivity technique. Using transient absorption measurements, we estimated the Efficiency of electron Injection for TiO 2 films in various solvents. Acetonitrile, which is widely considered to be the best solvent for solar cell performance, had the highest Efficiency (∼0.65), and other solvents (3-methoxypropionitrile, γ-butyrolactone, and propylene carbonate) had lower efficiencies. These results suggest that characteristic interactions between the black dye and the -CN groups of solvents are important for achieving higher electron Injection Efficiency.
Akihiro Furube - One of the best experts on this subject based on the ideXlab platform.
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Electron Injection Efficiency in dye-sensitized solar cells
Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2014Co-Authors: Ryuzi Katoh, Akihiro FurubeAbstract:Abstract Electron Injection processes in dye-sensitized solar cells (DSCs), which involve electron transfer from an excited dye to a semiconductor nanoparticle, have been discussed in many previously reported studies. In this review we discuss the working principles and primary processes of DSCs, as well as these processes’ influence on basic properties of solar cells such as open-circuit voltage, short-circuit current, and incident photon-to-current conversion Efficiency (IPCE). We focus our attention on the electron Injection process, and we introduce methods to determine electron Injection Efficiency ( Φ inj ) using time-resolved fluorescence and absorption spectroscopy techniques. We present difficulties associated with obtaining Φ inj by means of such techniques, and we propose nanosecond time-resolved transient absorption spectroscopy as a reliable method. Then, Φ inj values obtained are summarized. Factors limiting Φ inj are discussed from the perspective of free energy changes for electron Injection, the molecular structure of sensitizer dyes on the surface, and the presence of fast charge recombination pathways.
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Effect of dye coverage on photo-induced electron Injection Efficiency in N719-sensitized nanocrystalline TiO2 films
Chemical Physics Letters, 2010Co-Authors: Ryuzi Katoh, Akihiro Furube, Nobuhiro Fuke, Naoki KoideAbstract:The effect of dye coverage on the photo-induced electron Injection Efficiency in N719-sensitized nanocrystalline TiO2 films was studied by transient absorption spectroscopy. We evaluated the electron Injection Efficiency of films with several dye concentrations on the surface and found no significant difference between them. We also studied the suppression of the Efficiency by the addition of tBP (4-tert-butylpyridine) and found that the effect of tBP was more pronounced for films with lower dye loading. This suggests that sensitizer dyes adsorbed densely onto the surface suppress the adsorption of tBP.
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Quantitative study of solvent effects on electron Injection Efficiency for black-dye-sensitized nanocrystalline TiO2 films
Solar Energy Materials and Solar Cells, 2009Co-Authors: Ryuzi Katoh, Motohiro Kasuya, Akihiro Furube, Nobuhiro Fuke, Naoki Koide, Liyuan HanAbstract:The effects of various solvents on the electron Injection Efficiency for nanocrystalline TiO 2 films sensitized with the black dye trithiocyanato(4,4',4"-tricarboxy-2,2':6',2"-terpyridine)ruthenium(II) (Ru(tcterpy)(NCS) 3 ) have been studied quantitatively. The electron Injection Efficiency for the film dried in air was estimated as 0.4 using a time-resolved microwave conductivity technique. Using transient absorption measurements, we estimated the Efficiency of electron Injection for TiO 2 films in various solvents. Acetonitrile, which is widely considered to be the best solvent for solar cell performance, had the highest Efficiency (∼0.65), and other solvents (3-methoxypropionitrile, γ-butyrolactone, and propylene carbonate) had lower efficiencies. These results suggest that characteristic interactions between the black dye and the -CN groups of solvents are important for achieving higher electron Injection Efficiency.
Guanglong Sheng - One of the best experts on this subject based on the ideXlab platform.
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A New Methodology for the Multilayer Tight Oil Reservoir Water Injection Efficiency Evaluation and Real-Time Optimization
Geofluids, 2020Co-Authors: Lin Cao, Jianlong Xiu, Hongjie Cheng, Hui Wang, Shujian Xie, Hui Zhao, Guanglong ShengAbstract:It is important to determine the reasonable Injection and production rates in the development of multilayer tight oil reservoir with water flooding treatment. Based on the INSIM (interconnection-based numeric simulation model), a connected network model, a new method is designed to evaluate the water Injection Efficiency of different layers in water flooding reservoirs and to optimize the Injection-production system to produce more oil. Based on the types of sedimentary facies and corresponding Injection-production data, the interwell connections are divided into four major categories (middle channel, channel edge, middle channel bar, and channel bar edge) and twelve subclasses. This classification standard of interwell connections could help to significantly improve the accuracy of judging the dominant flow path without constructing a complicated geological model. The interaction of interwells such as Injection-production correlation and water Injection Efficiency could be revealed by simulating the production performance and computing the layer dividing coefficient and well dividing coefficient. A numerical example is used to validate this method by comparing results from FrontSim and this method, and the computational Efficiency of this method is several dozen times faster than that of the traditional numerical simulation. This method is applied to quickly optimize the production schedule of a tight oil reservoir with the water flooding treatment, that is, the water Injection rate of multilayer reservoirs could be optimized subtly by the Injection Efficiency of different layers, and the target of producing more oil with lower water cut could be achieved.