1,720,974 research outputs found
Nanorod metal oxide based electrodes and their application in hybrid photovoltaics
No full textAs a result of quickly increasing energy consumption, together with the need to produce this energy in a clean and sustainable fashion, photovoltaics is attracting abundant interest in the scientific community. Nowadays, the third generation photovoltaics poses a promising approach to further lower the production cost of solar cells. One of the representatives in this breed of photovoltaics is the hybrid solar cell, which is based on the combination of an inorganic and an organic semiconductor. Generally, an n-type inorganic semiconductor acts as the electron acceptor and a p-type semiconducting polymer serves as an light absorber and electron donor. Currently, metal-oxides such as ZnO and TiO2 have attracted a lot of of interest for the integration into hybrid solar cells due to their low-cost synthesis, reduced amount of toxicity compared to other inorganic semiconductors, good stability, and convenient electrical and optical properties. The big challenge remains to control the dimensions and morphology of metal oxides for the development of hybrid solar cells with high performances. To this end, vertically ordered nanorods arrays are a promising solution. Charge transport is highly dependent on the pathway of the charge carriers, so the one-dimensional structure of the nanorods provides a highway for electrons to the electrode. Moreover, this morphology ensures a large interface where electron-whole pairs can be split. In this PhD-thesis, we demonstrate the latest developments in our research towards application of metal oxides nanorod arrays/polymer for hybrid solar cells. Recently, we published a 40% increase in efficiency and for hydrothermally grown ZnO nanorods combined with poly-(3-hexylthiophene-2,5-diyl)(P3HT) through optimization of the ZnO/polymer interfacial area in combination with appropriate blocking layers for holes and electrons. Further enhancement of the efficiency for this type of solar cells is achieved by controlling the diameter and the packing density of the metal oxide nanorods, which lead to a record efficiency for ZnO nanorods/P3HT hybrid solar cells. Another important highlight, from an environmental point of view, is the possibility of creating a fully water-based hybrid solar cell. This work demonstrates the potential of hybrid photovoltaics and their viability concerning environmentally friendly device processing
Nanorod metal oxide based electrodes and their application in hybrid photovoltaics
No full textAs a result of quickly increasing energy consumption, together with the need to produce this energy in a clean and sustainable fashion, photovoltaics is attracting abundant interest in the scientific community. Nowadays, the third generation photovoltaics poses a promising approach to further lower the production cost of solar cells. One of the representatives in this breed of photovoltaics is the hybrid solar cell, which is based on the combination of an inorganic and an organic semiconductor. Generally, an n-type inorganic semiconductor acts as the electron acceptor and a p-type semiconducting polymer serves as an light absorber and electron donor. Currently, metal-oxides such as ZnO and TiO2 have attracted a lot of of interest for the integration into hybrid solar cells due to their low-cost synthesis, reduced amount of toxicity compared to other inorganic semiconductors, good stability, and convenient electrical and optical properties. The big challenge remains to control the dimensions and morphology of metal oxides for the development of hybrid solar cells with high performances. To this end, vertically ordered nanorods arrays are a promising solution. Charge transport is highly dependent on the pathway of the charge carriers, so the one-dimensional structure of the nanorods provides a highway for electrons to the electrode. Moreover, this morphology ensures a large interface where electron-whole pairs can be split. In this PhD-thesis, we demonstrate the latest developments in our research towards application of metal oxides nanorod arrays/polymer for hybrid solar cells. Recently, we published a 40% increase in efficiency and for hydrothermally grown ZnO nanorods combined with poly-(3-hexylthiophene-2,5-diyl)(P3HT) through optimization of the ZnO/polymer interfacial area in combination with appropriate blocking layers for holes and electrons. Further enhancement of the efficiency for this type of solar cells is achieved by controlling the diameter and the packing density of the metal oxide nanorods, which lead to a record efficiency for ZnO nanorods/P3HT hybrid solar cells. Another important highlight, from an environmental point of view, is the possibility of creating a fully water-based hybrid solar cell. This work demonstrates the potential of hybrid photovoltaics and their viability concerning environmentally friendly device processing
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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