1,720,967 research outputs found
Field emission characteristics of CoSi2/TiN-coated silicon emitter tips
No full textA CoSi2/TiN bilayer was coated on Si emitter tips and the emission characteristics of the tips were investigated. The CoSi2 layer was grown in situ by a reactive chemical vapor deposition of cyclopentadienyl dicarbonyl cobalt at 650 degreesC and then the TiN was deposited on the CoSi2 layer at 550 degreesC by a reactive sputtering of Ti with gas a reactive gas. The CoSi2 layer was conformally coated on the Si tips and the TiN layer adhered well to the CoSi2 layer. The CoSi2/MN-coated emitters showed a low turn-on voltage due to the low work function by TiN and a steep current increase caused by CoSi2. The current fluctuation of the CoSi2/TiN-coated Si emitter was smaller than that of the TiN-coated emitter. The long-term emission stability of the CoSi2/TiN-coated Si emitter was also greatly improved compared to the CoSi2-coated emitter because of the superior high temperature stability of the TiN layer. (C) 2002 Elsevier Science B.V. All rights reserved
Photovoltaic properties of CdTe solar cells fabricated by close spaced sublimation with screen printed CdTe sources
No full textScreen printed CdTe layer was employed as a source for close spaced sublimation process. By controlling the initial mixture of screen printed sourer, the Cd content in the CdTe film varied from 49.5% to 48%. The solar efficiency of CBD CdS/CdTe cell strongly depended on the stoichiometry of CdTe films due the bulk resistivity change ranging from 2x10(6) to 3 x 10(4) Omega cm. By comparing with the dark forward current of screen printed CdS/CdTe cell, it is suggested that in the CBD CdS/CdTe cell the grain size of CBD CdS layer should he increased to reduce the interface leakage current at low forward bias
Growth of in situ CoSi2 layer by metalorganic chemical vapor deposition on Si tips and its field-emission properties
No full textWe prepared Si emitters coated with a metalorganic chemical vapor deposited CoSi2 layer to improve emission properties. The CoSi2 layer was grown in situ by reactive chemical vapor deposition of cyclopentadienyl dicarbonyl cobalt at 650 degreesC. The CoSi2 layer was conformally deposited on the Si emitter tips and had a twinned structure at the epitaxial CoSi2/Si interface in the partial region. The CoSi2-coated Si emitters showed an enhanced emission due to the increase in the number of emitting sites from the Fowler-Nordheim plot. The fluctuation of emission current was reduced by the CoSi2 coating. But the long-term stability was not much improved, which may be due to the decrease of the field enhancement factor and the number of emitting sites of the CoSi2-coated Si tip. (C) 2001 American Vacuum Society
Field emission characteristics of COSi2/TaN-coated silicon emitter tips
No full textThis work has improved the emission characteristics of Si emitter tips by coating a CoSi2/TaN bilayer on the tips. The CoSi2 layer was grown in situ by a reactive chemical-vapor deposition of cyclopentadienyl dicarbonyl cobalt at 650 degreesC. The TaN was then deposited on the CoSi2 layer at 550 degreesC by a reactive sputtering of Ta with N as a reactive gas. The CoSi2/TaN-coated emitters showed a lower turn-on voltage and higher emission current than the CoSi2- or TaN-coated emitters due to the low work function by TaN and the easy transport of electron by CoSi2 with low resistivity. The long-term emission stability of CoSi2/TaN-coated Si emitter was as good as TaN-coated emitter
Photovoltaic properties of close-space sublimated CdTe solar cells
No full textCdS/CdTe solar cells were fabricated by close-space sublimation with a screen-printed Te-rich CdTe source and their photovoltaic properties were investigated by varying the substrate temperature, cell area, and thicknesses of CdTe and ITO layers. The resistivity of CdTe layers employed in this study was 3 x 10(4) Omega cm. The optimum substrate temperature and thickness for CdTe deposition were 600 degrees C and 5 mu m, respectively. The CdTe bulk resistance degraded the cell performance above 6 mu m. As the cell area increased the V-oc remained almost constant, while the J(ae) and FF were strongly degraded because of the increase of the lateral resistance of the ITO layer. The optimum thickness of the ITO layer in this study was 300-450 nm. In this experiment we obtained an efficiency of 9.4% in the 0.5 cm(2) cells. The series resistance of the cell should be further reduced to increase the fill factor and improve the efficiency. (C) 1998 Elsevier Science Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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