1,720,970 research outputs found
Non-covalent interaction engineering to tune the structural, optical, and electronic properties of layered hybrid perovskites
No full textOur society currently experiences an energy transition away from oil-, coal-, and natural gas-based energy sources towards more sustainable and environmentally less harmful energy sources, such as sunlight and wind power. Key to this energy transition are advanced materials that can efficiently harvest and consume energy from sustainable sources to generate electricity, light etc. Hybrid perovskites, which are the subject of this dissertation, are an example of such advanced materials to facilitate the energy transition. Over the past 15 years, hybrid perovskites have delivered high-performance solar cells, LEDs, lasers, transistors, and photodetectors.
By investigating layered hybrid perovskites with enhanced non-covalent interactions, we hope to shift the mindset of the perovskite researcher from inorganic chemistry, which has been dominating the perovskite field for the past decades, to organic chemistry, where especially the field of organic semiconductors holds the promise to produce excellent perovskite-based material systems and devices to power the global energy transition.This research has been funded by Bijzonder Onderzoeksfonds UHasselt (BOF) and Fonds Wetenschappelijk Onderzoek Vlaanderen (FWO). This work has been carried out in the context of the EnergyVille consortium, of which Hasselt University is a member
Non-covalent interaction engineering to tune the structural, optical, and electronic properties of layered hybrid perovskites
No full textOur society currently experiences an energy transition away from oil-, coal-, and natural gas-based energy sources towards more sustainable and environmentally less harmful energy sources, such as sunlight and wind power. Key to this energy transition are advanced materials that can efficiently harvest and consume energy from sustainable sources to generate electricity, light etc. Hybrid perovskites, which are the subject of this dissertation, are an example of such advanced materials to facilitate the energy transition. Over the past 15 years, hybrid perovskites have delivered high-performance solar cells, LEDs, lasers, transistors, and photodetectors.
By investigating layered hybrid perovskites with enhanced non-covalent interactions, we hope to shift the mindset of the perovskite researcher from inorganic chemistry, which has been dominating the perovskite field for the past decades, to organic chemistry, where especially the field of organic semiconductors holds the promise to produce excellent perovskite-based material systems and devices to power the global energy transition.This research has been funded by Bijzonder Onderzoeksfonds UHasselt (BOF) and Fonds Wetenschappelijk Onderzoek Vlaanderen (FWO). This work has been carried out in the context of the EnergyVille consortium, of which Hasselt University is a member
Multi-layered hybrid perovskites templated with carbazole derivatives: Optical properties, enhanced moisture stability and solar cell characteristics
No full textResearch into 2D layered hybrid perovskites is on the rise due to the enhanced stability of these materials compared to 3D hybrid perovskites. Recently, interest towards the use of functional organic cations for these materials is increasing. However, a vast amount of the parameter space remains unexplored in multi-layered (n > 1) hybrid perovskites for solar cell applications. Here, we incorporate carbazole derivatives as a proof of concept towards the use of tailored functional molecules in multi-layered perovskites. Films of low-n carbazole containing perovskites show high photoconductivity half-lifetimes. Higher-n (〈n〉 = 40) multi-layered perovskite films possess charge carrier diffusion lengths comparable to MAPI thin films. Solar cells containing these materials have comparable efficiencies to our MAPI and phenethylammonium (PEA)-containing multi-layered perovskite reference devices. Moisture stability tests were performed both at the material and device levels. In comparison to MAPI and PEA-based materials and solar cells, the addition of a small percentage of the carbazole derivative to the perovskite material significantly enhances the moisture stability.ChemE/Opto-electronic Material
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
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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