The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Helmut Stiebig - One of the best experts on this subject based on the ideXlab platform.
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Recombination Lifetime in Microcrystalline Silicon Absorbers of Highly Efficient Thin-Film Solar Cells
MRS Proceedings, 2011Co-Authors: T. Brammer, Helmut StiebigAbstract:AbstractAbsorber layers of microcrystalline silicon thin-film solar cells deposited by plasma-enhanced chemical vapor deposition are characterized regarding the Recombination Lifetime. The characterization is based on a comparison of experimentally determined solar cell characteristics with results from numerical device simulations. Evaluation of the dark reverse saturation current indicates a strong dependence of τ on the hydrogen dilution during the deposition. Close to the transition region to amorphous growth where the highest solar cell efficiencies are observed τ is maximum within the crystalline deposition regime and equals 30 ns.
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defect density and Recombination Lifetime in microcrystalline silicon absorbers of highly efficient thin film solar cells determined by numerical device simulations
Journal of Applied Physics, 2003Co-Authors: T. Brammer, Helmut StiebigAbstract:The absorber layers of microcrystalline silicon thin-film solar cells with p-i-n structure deposited by plasma-enhanced chemical vapor deposition at 200 °C are characterized regarding the defect density and the Recombination Lifetime. The characterization is based on a comparison of experimentally determined solar cell characteristics with results from numerical device simulations. Evaluation of the dark reverse saturation current indicates a strong dependence of the Recombination Lifetime τ on the hydrogen dilution during the deposition. Close to the transition region to amorphous growth, where the highest solar cell efficiencies are observed, τ is maximum within the crystalline deposition regime and equals around 80 ns. The aspect of a spatially varying defect density within the absorber layer is also addressed by numerical simulations. The results from the analysis of the dark current are compared with electron spin resonance data determined on single layers, which allows conclusions to be drawn regard...
Toshihide Takagahara - One of the best experts on this subject based on the ideXlab platform.
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Effects of Dimensionality on Radiative Recombination Lifetime of Excitons in Thin Quantum Boxes of Intermediate Regime between Zero and Two Dimensions
Japanese Journal of Applied Physics, 1997Co-Authors: Hideki Gotoh, H Ando, Toshihide Takagahara, Hidehiko Kamada, Arturo Chavez-pirson, Jiro TemmyoAbstract:We report on effects of dimensionality on radiative Recombination Lifetime in thin quantum boxes of intermediate regime between 0D and 2D. The temperature dependence of the Recombination Lifetime is calculated using a theoretical analysis that rigorously treats the electron-hole Coulomb interaction. We show how the dependence evolves from 2D to 0D with a decrease in the lateral width of the box. We also examine the effects of exciton localization, which arises from structural defects in the boxes, on the radiative Recombination Lifetime. These theoretical results are compared with experimental data obtained from InGaAs quantum disks on a (311)B GaAs substrate. Good agreement between theoretical results and the experimental data is obtained.
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radiative Recombination Lifetime of excitons in thin quantum boxes
Journal of Applied Physics, 1997Co-Authors: Hideki Gotoh, H Ando, Toshihide TakagaharaAbstract:Exciton radiative Recombination Lifetime in a thin quantum box in the intermediate spatial dimension between the two-dimension and the zero-dimension is investigated by a theoretical analysis which rigorously treats the electron-hole Coulomb interaction. The higher exciton states as well as the ground exciton state are explicitly taken into account to estimate the temperature dependence of exciton Recombination Lifetime. We clarify how the temperature dependence of the Recombination Lifetime varies with a change in the quantum confinement dimension which can be controlled by the lateral width of a thin quantum box. We also discuss the effect of the exciton localization due to structural imperfection on the radiative Recombination Lifetime.
P. Spirito - One of the best experts on this subject based on the ideXlab platform.
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Experimental measurements of Recombination Lifetime in proton irradiated power devices
12th International Symposium on Power Semiconductor Devices & ICs. Proceedings (Cat. No.00CH37094), 2000Co-Authors: S. Daliento, A. Sanseverino, P. Spirito, G. Busatto, J. WissAbstract:Experimental measurements of the Recombination Lifetime profile induced by proton implantation processes are presented. Results show the capability of the differential technique to monitor Lifetime engineering processes.
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An improved test structure for Recombination Lifetime profile measurements in very thick silicon wafers
IEEE Electron Device Letters, 1999Co-Authors: S. Daliento, A. Sanseverino, P. SpiritoAbstract:A new test structure for Recombination Lifetime profile measurements has been designed and applied, for the first time, to the characterization of very thick bulk silicon wafers. The capability of the new test device to reject parasitic effects, affecting the reliability of the measure in bulk wafers, is shown by means of two-dimensional (2-D) simulations and experimental results. The proposed device has permitted the characterization of two P-type silicon bulk samples. For the first time a clear experimental evidence that the dopant acts as a Recombination center has been found in this kind of material.
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Parametric description of the effect of electron irradiation on Recombination Lifetime in silicon layers: an experimental approach
IEEE Transactions on Power Electronics, 1999Co-Authors: S. Daliento, A. Sanseverino, P. Spirito, L. ZeniAbstract:The aim of this paper is to perform an experimental investigation on the effects of electron beam irradiation on the Recombination Lifetime of both p-type and n-type silicon layers in order to provide a set of parameters useful to model the Recombination effects in semiconductor computer simulation package. To this goal, the authors propose to use a proper three-terminal test structure in order to extract these parameters directly from Lifetime measurements along the silicon layers at different temperatures and at different injection levels by using the same silicon samples before and after the electron irradiation process in order to highlight the effects of the irradiation itself on the Lifetime. The experimental results indicate that the electron irradiation is more effective for controlling the high-injection Lifetime in p-type silicon than in an n-type one. The effect of the irradiation on Lifetime can be basically taken into account by means of one energy level placed at 0.27 eV below the conduction band edge for both n-type and p-type material, with /spl sigma//sub p//spl cong/10 /spl sigma//sub n/.
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Interferometric measurement of electron-hole pair Recombination Lifetime as a function of the injection level
IEEE Electron Device Letters, 1993Co-Authors: G. Breglio, P. Spirito, A. Cutolo, L. ZeniAbstract:The authors describe an interferometric technique for the measurement of the Recombination Lifetime of electron-hole pairs as a function of their concentration, which can be measured with an error smaller than 10%. In addition, the approach is much more sensitive than the other optical methods described in the literature.
F. Shimura - One of the best experts on this subject based on the ideXlab platform.
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Temperature Dependent Recombination Lifetime in Silicon: Influence of Trap Level
MRS Proceedings, 2011Co-Authors: A. Buczkowski, F. Shimura, Zbigniew J. Radzimski, Yoshi Kirino, George RozgonyiAbstract:This paper discusses the temperature dependence of Recombination Lifetime in a variety of silicon materials using energy level as a parameter. A theoretical approach based on the Shockley-Read-Hall theory for energy level calculations has been used. Various types of defects created by introducing impurities, dislocations and grain boundaries into silicon waferswere studied. Results are presented for Czochralski grown Si wafers intentionally contaminated with gold and chromium, EFG ribbon with varying concentration of oxygen, web ribbons with extended defects and contaminants, large grain polycrystalline material, and Si/Si-Ge/Si heterostructures with varying misfit and threading dislocation density.
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Influence of Crystal Thermal History on Surface Recombination Lifetime at Elevated Temperatures in Magnetic-Field-Applied Czochralski Silicon
Japanese Journal of Applied Physics, 1994Co-Authors: Hiroshi Daio, Adam Buczkowski, F. ShimuraAbstract:Recombination Lifetime for wafers prepared from two magnetic-field-applied Czochralski (MCZ) silicon crystals with a different body length was analyzed using a laser/microwave photoconductance (LM-PC) technique with an algorithm to separate the surface and bulk components. It has been shown that the surface Lifetime dominantly contributes to the dependence of the effective Lifetime at elevated temperatures on the crystal length. It is interpreted that the surface Lifetime is strongly affected by the grown-in defects which depend on the thermal history, or the crystal length of the silicon crystals.
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separation of the bulk and surface components of Recombination Lifetime obtained with a single laser microwave photoconductance technique
Journal of Applied Physics, 1992Co-Authors: A. Buczkowski, Z J Radzimski, G A Rozgonyi, F. ShimuraAbstract:An algorithm for separating the bulk and surface components of Recombination Lifetime obtained via a contactless single laser excitation/microwave reflection decay measurement is presented. The surface Recombination component of Lifetime is determined by extrapolating the tail portion of the carrier decay curve to the carrier axis. Although the slope of this curve depends on both surface and bulk properties, it is shown that the y intercept depends only on the surface component of Lifetime. A wide range of surface Lifetimes, corresponding to surface Recombination velocities from 102 to 105 cm/s, and bulk Lifetimes from a few microseconds to several hundred microseconds can be measured. An experimental verification of the analysis is presented using microwave absorption/reflection measurements on silicon wafers representing a wide variety of bulk and surface Lifetime components.
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bulk and surface components of Recombination Lifetime based on a two laser microwave reflection technique
Journal of Applied Physics, 1991Co-Authors: A. Buczkowski, Z J Radzimski, G A Rozgonyi, F. ShimuraAbstract:An algorithm for separating the bulk and surface components of Recombination Lifetime, tailored for contactless measurement techniques with laser excitation, is presented in the paper. In order to analyze the carrier decays and subtract the surface Recombination term, two lasers operating at 910 and 830 nm are applied. A separation of carrier decay resulting from the different contribution of surface and bulk components due to difference in the light absorption is observed for such a case. This separation is a function of surface Recombination velocity S. An experimental verification of the analysis is presented using microwave absorption/reflection measurements.
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Bulk and surface components of Recombination Lifetime based on a two‐laser microwave reflection technique
Journal of Applied Physics, 1991Co-Authors: A. Buczkowski, Zbigniew J. Radzimski, George Rozgonyi, F. ShimuraAbstract:An algorithm for separating the bulk and surface components of Recombination Lifetime, tailored for contactless measurement techniques with laser excitation, is presented in the paper. In order to analyze the carrier decays and subtract the surface Recombination term, two lasers operating at 910 and 830 nm are applied. A separation of carrier decay resulting from the different contribution of surface and bulk components due to difference in the light absorption is observed for such a case. This separation is a function of surface Recombination velocity S. An experimental verification of the analysis is presented using microwave absorption/reflection measurements.
T. Brammer - One of the best experts on this subject based on the ideXlab platform.
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Recombination Lifetime in Microcrystalline Silicon Absorbers of Highly Efficient Thin-Film Solar Cells
MRS Proceedings, 2011Co-Authors: T. Brammer, Helmut StiebigAbstract:AbstractAbsorber layers of microcrystalline silicon thin-film solar cells deposited by plasma-enhanced chemical vapor deposition are characterized regarding the Recombination Lifetime. The characterization is based on a comparison of experimentally determined solar cell characteristics with results from numerical device simulations. Evaluation of the dark reverse saturation current indicates a strong dependence of τ on the hydrogen dilution during the deposition. Close to the transition region to amorphous growth where the highest solar cell efficiencies are observed τ is maximum within the crystalline deposition regime and equals 30 ns.
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defect density and Recombination Lifetime in microcrystalline silicon absorbers of highly efficient thin film solar cells determined by numerical device simulations
Journal of Applied Physics, 2003Co-Authors: T. Brammer, Helmut StiebigAbstract:The absorber layers of microcrystalline silicon thin-film solar cells with p-i-n structure deposited by plasma-enhanced chemical vapor deposition at 200 °C are characterized regarding the defect density and the Recombination Lifetime. The characterization is based on a comparison of experimentally determined solar cell characteristics with results from numerical device simulations. Evaluation of the dark reverse saturation current indicates a strong dependence of the Recombination Lifetime τ on the hydrogen dilution during the deposition. Close to the transition region to amorphous growth, where the highest solar cell efficiencies are observed, τ is maximum within the crystalline deposition regime and equals around 80 ns. The aspect of a spatially varying defect density within the absorber layer is also addressed by numerical simulations. The results from the analysis of the dark current are compared with electron spin resonance data determined on single layers, which allows conclusions to be drawn regard...