Institution
Johannes Kepler University of Linz
Education•Linz, Oberösterreich, Austria•
About: Johannes Kepler University of Linz is a education organization based out in Linz, Oberösterreich, Austria. It is known for research contribution in the topics: Computer science & Thin film. The organization has 6605 authors who have published 19243 publications receiving 385667 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the authors present a platform that makes electronics both virtually unbreakable and imperceptible on polyimide polysilicon elastomers, which can be operated at high temperatures and in aqueous environments.
Abstract: Electronic devices have advanced from their heavy, bulky origins to become smart, mobile appliances. Nevertheless, they remain rigid, which precludes their intimate integration into everyday life. Flexible, textile and stretchable electronics are emerging research areas and may yield mainstream technologies. Rollable and unbreakable backplanes with amorphous silicon field-effect transistors on steel substrates only 3 μm thick have been demonstrated. On polymer substrates, bending radii of 0.1 mm have been achieved in flexible electronic devices. Concurrently, the need for compliant electronics that can not only be flexed but also conform to three-dimensional shapes has emerged. Approaches include the transfer of ultrathin polyimide layers encapsulating silicon CMOS circuits onto pre-stretched elastomers, the use of conductive elastomers integrated with organic field-effect transistors (OFETs) on polyimide islands, and fabrication of OFETs and gold interconnects on elastic substrates to realize pressure, temperature and optical sensors. Here we present a platform that makes electronics both virtually unbreakable and imperceptible. Fabricated directly on ultrathin (1 μm) polymer foils, our electronic circuits are light (3 g m(-2)) and ultraflexible and conform to their ambient, dynamic environment. Organic transistors with an ultra-dense oxide gate dielectric a few nanometres thick formed at room temperature enable sophisticated large-area electronic foils with unprecedented mechanical and environmental stability: they withstand repeated bending to radii of 5 μm and less, can be crumpled like paper, accommodate stretching up to 230% on prestrained elastomers, and can be operated at high temperatures and in aqueous environments. Because manufacturing costs of organic electronics are potentially low, imperceptible electronic foils may be as common in the future as plastic wrap is today. Applications include matrix-addressed tactile sensor foils for health care and monitoring, thin-film heaters, temperature and infrared sensors, displays, and organic solar cells.
2,062 citations
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TL;DR: In this article, a post-production treatment that improves the performance of solar cells based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) was developed.
Abstract: Efficiencies of organic solar cells based on an interpenetrating network of a conjugated polymer and a fullerene as donor and acceptor materials still need to be improved for commercial use. We have developed a postproduction treatment that improves the performance of solar cells based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) by means of a tempering cycle at elevated temperatures in which an external voltage is simultaneously applied, resulting in a significant increase of the short-circuit current. Using this postproduction treatment, an enhancement of the short-circuit current density, Isc, to 8.5 mA cm–2 under illumination with white light at an illumination intensity of 800 W m–2 and an increase in external quantum efficiency (IPCE, incident photon to collected electron efficiency) to 70 % are demonstrated.
2,040 citations
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University of Maryland, College Park1, Queen's University2, Cornell University3, University of Minnesota4, Nanyang Technological University5, McKinsey & Company6, Koç University7, Jacobs University Bremen8, University of Minho9, The Chinese University of Hong Kong10, Indian Institute of Management Ahmedabad11, Pontifical Catholic University of Peru12, University of Valencia13, Johannes Kepler University of Linz14, Victoria University of Wellington15, Hungarian Academy of Sciences16, National and Kapodistrian University of Athens17, La Trobe University18, University of Melbourne19, Sungkyunkwan University20, ESSEC Business School21, University of San Diego22, Katholieke Universiteit Leuven23, University of Patras24, Human Sciences Research Council25, ODESSA26, University of Tartu27, Norwegian School of Economics28, University of Koblenz and Landau29, University of Sussex30, University of Sindh31, Gakushuin University32, University of Groningen33, University of Tokyo34
TL;DR: The differences across cultures in the enforcement of conformity may reflect their specific histories and advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change.
Abstract: With data from 33 nations, we illustrate the differences between cultures that are tight (have many strong norms and a low tolerance of deviant behavior) versus loose (have weak social norms and a high tolerance of deviant behavior). Tightness-looseness is part of a complex, loosely integrated multilevel system that comprises distal ecological and historical threats (e.g., high population density, resource scarcity, a history of territorial conflict, and disease and environmental threats), broad versus narrow socialization in societal institutions (e.g., autocracy, media regulations), the strength of everyday recurring situations, and micro-level psychological affordances (e.g., prevention self-guides, high regulatory strength, need for structure). This research advances knowledge that can foster cross-cultural understanding in a world of increasing global interdependence and has implications for modeling cultural change.
1,895 citations
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TL;DR: A series of highly soluble fullerene derivatives with varying acceptor strengths (i.e., first reduction potentials) was synthesized and used as electron acceptors in plastic solar cells as discussed by the authors.
Abstract: A series of highly soluble fullerene derivatives with varying acceptor strengths (i.e., first reduction potentials) was synthesized and used as electron acceptors in plastic solar cells. These fullerene derivatives, methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM), a new azafulleroid, and a ketolactam quasifullerene, show a variation of almost 200 mV in their first reduction potential. The open circuit voltage of the corresponding devices was found to correlate directly with the acceptor strength of the fullerenes, whereas it was rather insensitive to variations of the work function of the negative electrode. These observations are discussed within the concept of Fermi level pinning between fullerenes and metals via surface charges.
1,807 citations
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08 Aug 2006TL;DR: This book should help newcomers to the field to understand how finite mixture and Markov switching models are formulated, what structures they imply on the data, what they could be used for, and how they are estimated.
Abstract: WINNER OF THE 2007 DEGROOT PRIZE!
The prominence of finite mixture modelling is greater than ever. Many important statistical topics like clustering data, outlier treatment, or dealing with unobserved heterogeneity involve finite mixture models in some way or other. The area of potential applications goes beyond simple data analysis and extends to regression analysis and to non-linear time series analysis using Markov switching models.
For more than the hundred years since Karl Pearson showed in 1894 how to estimate the five parameters of a mixture of two normal distributions using the method of moments, statistical inference for finite mixture models has been a challenge to everybody who deals with them. In the past ten years, very powerful computational tools emerged for dealing with these models which combine a Bayesian approach with recent Monte simulation techniques based on Markov chains. This book reviews these techniques and covers the most recent advances in the field, among them bridge sampling techniques and reversible jump Markov chain Monte Carlo methods.
It is the first time that the Bayesian perspective of finite mixture modelling is systematically presented in book form. It is argued that the Bayesian approach provides much insight in this context and is easily implemented in practice. Although the main focus is on Bayesian inference, the author reviews several frequentist techniques, especially selecting the number of components of a finite mixture model, and discusses some of their shortcomings compared to the Bayesian approach.
The aim of this book is to impart the finite mixture and Markov switching approach to statistical modelling to a wide-ranging community. This includes not only statisticians, but also biologists, economists, engineers, financial agents, market researcher, medical researchers or any other frequent user of statistical models. This book should help newcomers to the field to understand how finite mixture and Markov switching models are formulated, what structures they imply on the data, what they could be used for, and how they are estimated. Researchers familiar with the subject also will profit from reading this book. The presentation is rather informal without abandoning mathematical correctness. Previous notions of Bayesian inference and Monte Carlo simulation are useful but not needed.
1,642 citations
Authors
Showing all 6718 results
Name | H-index | Papers | Citations |
---|---|---|---|
Wolfgang Wagner | 156 | 2342 | 123391 |
A. Paul Alivisatos | 146 | 470 | 101741 |
Klaus-Robert Müller | 129 | 764 | 79391 |
Christoph J. Brabec | 120 | 896 | 68188 |
Andreas Heinz | 108 | 1078 | 45002 |
Niyazi Serdar Sariciftci | 99 | 591 | 54055 |
Lars Samuelson | 96 | 850 | 36931 |
Peter J. Oefner | 90 | 348 | 30729 |
Dmitri V. Talapin | 90 | 303 | 39572 |
Tomás Torres | 88 | 625 | 28223 |
Ramesh Raskar | 86 | 670 | 30675 |
Siegfried Bauer | 84 | 422 | 26759 |
Alexander Eychmüller | 82 | 444 | 23688 |
Friedrich Schneider | 82 | 554 | 27383 |
Maksym V. Kovalenko | 81 | 360 | 34805 |