1,720,975 research outputs found
Two different effects of Na on Cu2ZnSnS4 thin-film solar cells
No full textAmong the many factors that affect the characteristics of Cu2ZnSnS4 thin-film solar cells, the effects of Na were examined. Because Na passivates the grain boundaries (GBs) in absorber layers, the GBs increase the minority carrier collection by providing a current pathway through which the minority carriers can reach the buffer and window layer and be collected. However, excess Na remains in the absorber layer and diffuses into the buffer and window layers, where it acts as an impurity and traps the minority carriers, thus decreasing the solar cell characteristics. By applying an annealing process after the deposition of the buffer and window layers, the Na content could be decreased. By improving the solar cell characteristics, a power conversion efficiency of 6.43% was achieved. © 2015 Elsevier B.V.1
Improvement of Cu2ZnSnS4 Solar Cell Characteristics with Zn(O-x,S1-x) Buffer Layer
No full textThis experiment investigated characteristic changes in a Cu2ZnSnS4 (CZTS) solar cell by applying a Zn (O-x, S1-x) butter layer with various compositions on the upper side of the absorber layer. Among the four single layers such as Zn(O-0.76, S-0.24), Zn(O-0.56, S-0.44), Zn(O-0.33, S-0.67), and Zn(O-0.17, S-0.83), the Zn(O-0.76, S-0.24) buffer layer was applied to the device due to its bandgap structure for suppressing electron-hole recombination. In the application of the Zn(O-0.76, S-0.24) buffer layer to the device, the buffer layer in the device showed the composition of Zn(O-0.7, S-0.3) because S diffused into the buffer layer from the absorber layer. The Zn(O-0.7, S-0.3) buffer layer, having a lower energy level (E-V) than a CdS buffer layer, improved the J(SC) and V-OC characteristics of the CZTS solar cell because the Zn(O-0.7, S-0.3) buffer layer effectively suppressed electron-hole recombination. A substitution of the CdS buffer layer by the Zn(O-0.7, S-0.3) buffer layer improved the efficiency of the CZTS solar cell from 2.75% to 4.86%.1
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Hybrid solar cells with conducting polymers and vertically aligned silicon nanowire arrays: The effect of silicon conductivity
No full textOrganic/inorganic hybrid solar cells, based on vertically aligned n-type silicon nanowires (n-Si NWs) and p-type conducting polymers (PEDOT:PSS), were investigated as a function of Si conductivity. The n-Si NWs were easily prepared from the n-Si wafer by employing a silver nanodot-mediated micro- electrochemical redox reaction. This investigation shows that the photocurrent-to-voltage characteristics of the n-Si NW/PEDOT:PSS cells clearly exhibit a stable rectifying diode behavior. The increase in current density and fill factor using high conductive silicon is attributed to an improved charge transport towards the electrodes achieved by lowering the devices series resistance. Our results also show that the surface area of the nanowire that can form heterojunction domains significantly influences the device performance. © 2011 Elsevier B.V. All rights reserved.1
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