The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform
Kenneth Stuart Sorbie - One of the best experts on this subject based on the ideXlab platform.
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Depleted Layer effects in polymer flow through porous media ii network calculations
Journal of Colloid and Interface Science, 1990Co-Authors: Kenneth Stuart SorbieAbstract:Abstract This paper investigates the effects of surface exclusion in the rheology of polymers in network models of porous media. Here, the results developed for single capillary flow with Depleted Layers in Part I are incorporated into network calculations. Using input data based on the biopolymer, xanthan, a number of predictions are made on the macroscopic rheological behavior of solutions of this polymer in porous medium flow. It is found that the macroscopic “apparent slip” effect can be quite substantial even for fairly low Depleted Layer thicknesses compared with average pore size in the network.
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Depleted Layer effects in polymer flow through porous media i single capillary calculations
Journal of Colloid and Interface Science, 1990Co-Authors: Kenneth Stuart SorbieAbstract:Abstract Polymer molecules may be entropically excluded from a region of fluid close to the wall in a narrow capillary or flow channel in a porous medium. This effect results in a Layer of polymer-Depleted solution close to the wall which causes both apparent viscous slip effects and velocity enhancement of the polymer molecules relative to the solvent molecules. In this paper, theoretical calculations are presented on the effects of the Depleted Layer on the rheological and transport properties of the polymer solution in capillaries. This work extends earlier simple models to include more complex analytical forms of the Layer profile and flow rate effects.
F. Zocca - One of the best experts on this subject based on the ideXlab platform.
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An SiC/GaN Detector/Front-End Detection System for High-Resolution Alpha-Particle Spectroscopy
IEEE Transactions on Nuclear Science, 2008Co-Authors: A. Pullia, G. Bertuccio, D. Maiocchi, S. Caccia, F. ZoccaAbstract:An alpha-particle spectrometer has been assembled, consisting of an epitaxial 50 mum thick 4H silicon carbide (SiC) detector connected to a gallium-nitride (GaN) high-electron mobility transistor (HEMT) used as input transistor of the front-end electronics. The Depleted Layer of the SiC diode detector was sufficient to stop all alpha particles in the 4.8-MeV to 5.8-MeV energy range. An excellent energy resolution of ~ 0.9% has been obtained in this energy range at a temperature of 55degC. The energy-resolution limiting factor is found to be the dispersion of the energy loss in the gold Schottky contact, which acts as entrance window to the detector. We used a GaN front-end transistor because this material offers two important advantages over silicon: (1) it is a wide bandgap semiconductor and therefore is intrinsically more desirable for room and above-room temperature operation and (2) it can be grown on SiC substrates so as to realize SiC/GaN integrated systems. SiC-detector spectrometers are interesting in many nuclear applications where the operation environment is hostile, both in terms of ionising radiations and of high temperatures. Such applications include monitoring of ionising radiations in nuclear power plants and beam diagnostic in fundamental nuclear physics experiments.
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High-resolution alpha-particle spectroscopy with an hybrid SiC/GaN detector/front-end detection system
2007 IEEE Nuclear Science Symposium Conference Record, 2007Co-Authors: A. Pullia, G. Bertuccio, D. Maiocchi, S. Caccia, F. ZoccaAbstract:An alpha-particle spectrometer has been assembled, consisting of an epitaxial 50 mum thick 4H silicon carbide detector connected to a gallium nitride HEMT used as input transistor of the front-end electronics. The Depleted Layer of the SiC diode detector was sufficient to stop all alpha particles of the used emitter in the 4.8-MeV to 5.8-MeV energy range. An excellent energy resolution of ~0.9% has been obtained in this energy range at a temperature of 55degC, which is comparable to that of single-crystal diamond detectors. The energy-resolution limiting factor is found to be the dispersion of the energy loss in the gold Schottky contact, which acts as entrance window to the detector. We used a gallium nitride (GaN) front-end transistor because this material offers two important advantages against silicon: (i) it can be grown on SiC substrates so as to realize SiC/GaN integrated systems, (ii) it is a wide band-gap semiconductor and therefore is intrinsically more adequate for room and above-room temperature operation. SiC-detector spectrometers are interesting in many nuclear application where the operation environment is hostile, both in terms of ionising radiation contamination and of high temperatures. Such applications include monitoring of ionising radiations in nuclear power plants and beam diagnostic in fundamental nuclear physics experiments.
A. Pullia - One of the best experts on this subject based on the ideXlab platform.
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An SiC/GaN Detector/Front-End Detection System for High-Resolution Alpha-Particle Spectroscopy
IEEE Transactions on Nuclear Science, 2008Co-Authors: A. Pullia, G. Bertuccio, D. Maiocchi, S. Caccia, F. ZoccaAbstract:An alpha-particle spectrometer has been assembled, consisting of an epitaxial 50 mum thick 4H silicon carbide (SiC) detector connected to a gallium-nitride (GaN) high-electron mobility transistor (HEMT) used as input transistor of the front-end electronics. The Depleted Layer of the SiC diode detector was sufficient to stop all alpha particles in the 4.8-MeV to 5.8-MeV energy range. An excellent energy resolution of ~ 0.9% has been obtained in this energy range at a temperature of 55degC. The energy-resolution limiting factor is found to be the dispersion of the energy loss in the gold Schottky contact, which acts as entrance window to the detector. We used a GaN front-end transistor because this material offers two important advantages over silicon: (1) it is a wide bandgap semiconductor and therefore is intrinsically more desirable for room and above-room temperature operation and (2) it can be grown on SiC substrates so as to realize SiC/GaN integrated systems. SiC-detector spectrometers are interesting in many nuclear applications where the operation environment is hostile, both in terms of ionising radiations and of high temperatures. Such applications include monitoring of ionising radiations in nuclear power plants and beam diagnostic in fundamental nuclear physics experiments.
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High-resolution alpha-particle spectroscopy with an hybrid SiC/GaN detector/front-end detection system
2007 IEEE Nuclear Science Symposium Conference Record, 2007Co-Authors: A. Pullia, G. Bertuccio, D. Maiocchi, S. Caccia, F. ZoccaAbstract:An alpha-particle spectrometer has been assembled, consisting of an epitaxial 50 mum thick 4H silicon carbide detector connected to a gallium nitride HEMT used as input transistor of the front-end electronics. The Depleted Layer of the SiC diode detector was sufficient to stop all alpha particles of the used emitter in the 4.8-MeV to 5.8-MeV energy range. An excellent energy resolution of ~0.9% has been obtained in this energy range at a temperature of 55degC, which is comparable to that of single-crystal diamond detectors. The energy-resolution limiting factor is found to be the dispersion of the energy loss in the gold Schottky contact, which acts as entrance window to the detector. We used a gallium nitride (GaN) front-end transistor because this material offers two important advantages against silicon: (i) it can be grown on SiC substrates so as to realize SiC/GaN integrated systems, (ii) it is a wide band-gap semiconductor and therefore is intrinsically more adequate for room and above-room temperature operation. SiC-detector spectrometers are interesting in many nuclear application where the operation environment is hostile, both in terms of ionising radiation contamination and of high temperatures. Such applications include monitoring of ionising radiations in nuclear power plants and beam diagnostic in fundamental nuclear physics experiments.
Hiroshi Arimoto - One of the best experts on this subject based on the ideXlab platform.
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visualization of the Depleted Layer in nanoscaled pn junctions on si 001 surfaces with the use of scanning tunneling microscopy
Applied Surface Science, 1999Co-Authors: Hidenobu Fukutome, Shigehiko Hasegawa, Keizo Takano, Hisao Nakashima, T Aoyama, Hiroshi ArimotoAbstract:Abstract We demonstrate that the microscopic variation of the bulk electronic properties of nanoscaled pn junctions formed on Si(001) surface is clearly visualized with the use of scanning tunneling microscopy/scanning tunneling spectroscopy (STM/STS). The STM measurement reveals that it is possible to distinguish among the n-type the p-type and the Depleted p-type regions. It is shown that the contrasts between the regions strongly depend on the bias voltage for the STM measurement. Especially, for the negative sample bias voltage, it is observed that the width of the depletion Layer gets wider with decreasing the sample bias voltage. We will discuss the origin of the bias voltage dependence of the STM image in terms of a metal–insulator–semiconductor structure model. It is also shown that the current imaging tunneling spectroscopy image can also visualize three regions of the nanoscaled pn junctions.
Gary Hodes - One of the best experts on this subject based on the ideXlab platform.
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band diagram and effects of the kscn treatment in tio2 sb2s3 cuscn eta cells
Journal of Physical Chemistry C, 2016Co-Authors: Yafit Itzhaik, Tatyana Bendikov, Douglas A Hines, Prashant V Kamat, Hagai Cohen, Gary HodesAbstract:Thiocyanate ion treatment, usually either LiSCN or KSCN, of the absorbing semiconductor before deposition of a CuSCN hole conducting Layer is known to improve the performance of extremely thin absorber (ETA) solar cells by reducing the cell resistivity. However, in spite of several hypotheses, the mechanism behind this treatment outcome remains elusive. In this study, the interface between Sb2S3 and CuSCN in an ETA cell is investigated with surface spectroscopy and transient absorption spectroscopy to establish the mechanistic aspects of the KSCN treatment and the role it plays in improving the photovoltaic performance. The prominent factors that dictate the cell performance are (a) doping the interfacial CuSCN and thus preventing the formation of a sub-μm Depleted Layer and (b) passivating charge traps at the Sb2S(O)3 surface, which increases the rate of hole transfer from the absorber to the hole conductor. We further show that the treatment works just as well in improving photovoltaic performance when ...