1,721,044 research outputs found
Finite Element Simulation of the Local Al/Si Contact Formation
No full textAbstractThe formation of local Al/Si contacts, as found in PERC type cells, was evaluated by finite element simulation based on a model of Si diffusion in the molten Al layer as well as dissolution and recrystallization of Si at the liquid/solid interface. In accordance with experimental observations the simulations reproduce the characteristic lateral spread of Si in the Al layer, the different cavity shapes (ranging from round to ω-shaped cavities) as well as the development of the Al-doped recrystallized region which forms the high-low junction to the lower doped substrate responsible for the back surface field passivation
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
Instability of Dielectric Surface Passivation Quality at Elevated Temperature and Illumination
No full textAbstractHydrogenated silicon nitride and aluminum oxide passivation layers were deposited on boron doped floatzone silicon wafers that underwent a high temperature firing step. The passivation quality was monitored during thermal treatment at 75°C, 150°C and 250°C in darkness or under illumination. It was found that the passivation quality of the specific layers under investigation is far from stable in the course of time showing both deterioration and improvement features on a time scale of minutes to weeks. Furthermore, it was found that these changes occur in both darkness and under illumination, whereupon (stronger) illumination accelerates the changes. Via corona charging and capacitance voltage experiments it could be shown that the observed changes in the short term are mainly caused by changes in the chemical passivation quality
Concepts and Techniques for the Analysis of Defect Reactions in Crystalline Silicon
No full textCrystalline silicon used for photovoltaic applications is one of the purest materials on earth used for mass production. Even small quantities of certain impurities or defects may seriously impair its electronic quality, in particular the excess charge carrier lifetime or the associated diffusion length being the most relevant figure-of-merit for solar cells made from crystalline silicon. And even though it is a solid, impurities may still move around and react with each other, eventually resulting in a delayed formation of harmful defects manifesting as degradation phenomena of which some are triggered under illumination.
Within this work, a variety of concepts and techniques used for the analysis of defect reactions in silicon is presented. At first, a mathematical description of reaction dynamics is given and different scenarios are discussed. It is then shown how defect density, or at least a proxy for it, can be inferred from measurements of excess charge carrier lifetime, or from open circuit voltage in case of solar cells. Furthermore, the problems regarding the correct quantification of surface recombination arising from limited excess charge carrier lifetime are explained. Moreover, a method is presented that allows for an assessment of iron contamination in solar cells from open circuit voltages. Lastly, a method for the quantification of hydrogen in crystalline silicon based on its reactions with other impurities is presented.
In addition, some side topics are covered as well, like the development of an LED-based illumination setup, a discussion on how (not) to report on illumination intensity, the problems encountered in intensity measurements, and problems in bifacial MIS-type samples used for the intentional manipulation of surface passivation quality.publishe
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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