1,720,955 research outputs found
Impact of Lithium as Interfacial Treatment for CZTSSe Solar Cells
No full textCu2ZnSn(S,Se)4 (CZTSSe), despite its slow progress in terms of efficiency, stands out as a viable option for solar cell absorber materials due to its comparatively low-cost fabrication process, and abundance of constituent elements. The efficiency of CZTSSe faces challenges, particularly a notable Voc deficit arising from its non-stoichiometric nature and interface recombination between CZTSSe and the buffer layer, thus deteriorating the performance of the device. Lithium doping has been known to be effective in tuning the band gap and modifying grain boundaries, enhancing device performance. It is essential to identify a direct and efficient method to address the challenges associated with significant lithium losses in in-situ doping processes. Herein, we demonstrate an effective approach to significantly increase the open-circuit voltage (VOC) and efficiency of the device via a simple impurity inclusion process: the surface of the precursor film is treated with chlorine-based compounds containing Li and Ge. This modification results in an efficiency of up to 7.2 %, with a significant improvement in Voc, indicating that the use of Ge and Li is a viable means of increasing efficiency by reducing defect density. The structural modifications are addressed by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Current-voltage, capacitance-voltage and drive-level capacitance profiling are used to analyze the performance and defect density of the finished devices
Investigation of CU2ZnSn(S, Se)4 Solar Cells Fabricated Through Aqueous Non-Vacuum Spray Deposition
No full textKesterite Cu2ZnSn(S, Se)4 (CZTSSe)- based solar cells have grown in popularity as an alternative to copper indium gallium selenide (CIGS) due to their outstanding features, such as low toxicity, cost-effectiveness, acceptable optoelectrical properties, and abundant materials. Our research focuses on spray coating, which is believed to be one of the most viable scalable techniques. In this work, we have employed a simple and cost-effective built-in spray coating to synthesize a phase-pure CZTSSe. Further research is required to gain an in-depth understanding of the spray coating process for CZTSSe solar cells, which is the objective of this work. This paper presents a comparative study of the devices' properties and performance between spray and spin coating, which is our standard fabrication system. It also provides different characterizations of the morphological, structural, and optoelectronic properties of CZTSSe absorbers and devices
CdCl2 Treatment for Cu2ZnSn(S,Se)4: A Method to Enhance the Solar Cell Performance
No full textUnlike other thin-film absorbers, CZTSSe can be efficiently produced using nonvacuum techniques, which enable precise control over the stoichiometry of the absorber layer from the precursor solution stage. Despite extensive research over the past two decades, CZTSSe has not surpassed an efficiency of 15%, primarily due to a significant V oc deficit. To address this challenge, researchers typically pursue either alloying the absorber with additional elements to tune the band gap or doping the absorber with impurities to boost carrier concentration. This study presents a straightforward approach for improving performance by either narrowing the band gap or doping the absorber by processing, for the first time, the CZTSSe by CdCl2 treatment, which can be applied to any fabrication process. Depending on the stage of the fabrication process at which it is carried out, the same practical CdCl2 treatment can introduce Cd into the CZTSSe matrix as an alloying or doping agent
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
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