1,721,062 research outputs found
Nanoscale morphology and electronic properties at the metal/semiconductor interface in organic light-emitting diodes
No full textMaterials morphology at the nanoscale and charge transport properties in organic field-effect transistors: an integrated MD/KMC approach
No full textDirect Comparison of the Effect of Processing Conditions in Electrolyte-Gated and Bottom-Gated TIPS-Pentacene Transistors
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Open AccessFeature PaperArticle
Direct Comparison of the Effect of Processing Conditions in Electrolyte-Gated and Bottom-Gated TIPS-Pentacene Transistors
by Nicolò Lago 1,*ORCID,Marco Buonomo 1,Federico Prescimone 2,Stefano Toffanin 2ORCID,Michele Muccini 2 andAndrea Cester 1
1
Department of Information Engineering, University of Padova, 35131 Padova, Italy
2
Institute of Nanostructured Materials (ISMN), National Research Council (CNR), 40129 Bologna, Italy
*
Author to whom correspondence should be addressed.
Academic Editor: Horng-Long Cheng
Electron. Mater. 2022, 3(4), 281-290; https://doi.org/10.3390/electronicmat3040024 (registering DOI)
Received: 6 September 2022 / Revised: 21 September 2022 / Accepted: 23 September 2022 / Published: 27 September 2022
(This article belongs to the Special Issue Feature Papers of Electronic Materials (Second Volume))
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Abstract
Among the plethora of soluble and easy processable organic semiconductors, 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-P5) is one of the most promising materials for next-generation flexible electronics. However, based on the information reported in the literature, it is difficult to exploit in field-effect transistors the high-performance characteristics of this material. This article correlates the HMDS functionalization of the silicon substrate with the electrical characteristics of TIPS-P5-based bottom gate organic field-effect transistors (OFETs) and electrolyte-gated organic field-effect transistors (EGOFETs) fabricated over the same platform. TIPS-P5 transistors with a double-gate architecture were fabricated by simple drop-casting on Si/SiO2 substrates, and the substrates were either functionalized with hexamethyldisilazane (HMDS) or left untreated. The same devices were characterized both as standard bottom-gate transistors and as (top-gate) electrolyte-gated transistors, and the results with and without HMDS treatment were compared. It is shown that the functionalization of the silicon substrate negatively influences EGOFETs performance, while it is beneficial for bottom-gate OFETs. Different device architectures (e.g., bottom-gate vs. top-gate) require specific evaluation of the fabrication protocols starting from the effect of the HMDS functionalization to maximize the electrical characteristics of TIPS-P5-based devices
Selective Self-Assembled Monolayer to Passivate Organic Cell Stimulating and Sensing Transistor (OCSTs)
No full textSelf-Assembled Monolayers (SAMs) on gold were successfully implemented to passivate gold contact organic cell
stimulating and sensing transistors. The results show the devices to be greatly insulated from water. This breakthrough is
proposed as a technological improvement for bio-stimulation and bio-sensing organic field-effect devices
Efficiency enhancement of P3HT:PCBM solar cells containing scattering Zn-Al hydrotalcite nanoparticles in the PEDOT:PSS layer
No full textIn this article we report on a new hybrid (organic-inorganic) composite material based on hydrophilic, electrically inert and semi-transparent hydrotalcite (HT) nanoparticles and a pHneutral formulation of PEDOT:PSS. The application of this composite material as electrically and optically active buffer layer in P3HT:PC61BM bulk heterojunction (BHJ) solar cells is reported. Two different synthetic routes are explored to obtain HTs having discoid shape, with a diameter of around 150- 200 nm and a thickness of ~20 nm, to be easily embedded in ~50 nm thick PEDOT:PSS films. The good affinity between HTs and the sulfonate groups of the PEDOT:PSS allows to obtain homogeneous HTs/PEDOT:PSS films, for HT concentrations of 0.25% and 0.50% by weight (vs. PEDOT:PSS). At these particle loads the electrical and morphological features of doped and undoped PEDOT:PSS films are nearly identical, while providing a significant effect on the visible light scattering properties of the composite films. We demonstrate ~12% improvement in power conversion efficiency (PCE) for P3HT:PC61BM solar cells incorporating HTs in the PEDOT: PSS layer, which mainly originates from increased shortcircuit current densities (JSC)
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
Efficient as-cast bulk-heterojunction solar cells based on a tert-butyl substituted methanofullerene acceptor
No full textWe report on the implementation of a modified methanofullerene PCBtB ([6,6]-phenyl-C(61) butyric acid tert-butylester) as electron acceptor for solution-processable bulk-heterojunction (BHJ) solar cells based on P3HT (poly(3-hexylthiophene)). The results demonstrate how a small modification of the steric hindrance of the benchmark molecule PCBM, leaving the electronic structure unchanged, significantly influences the main properties of the BHJ active layer. In particular, we investigate the effect of the replacement of the PC(61)BM methyl end-group with a tert-butyl substituent on the optical properties, OPV parameters, nanoscale morphology, D: A phase segregation, and charge carrier mobility in bulk-heterojunction with P3HT. We find that the PCBtB-based blends present a finer self-organization, higher D: A phase segregation and good charge carrier mobility, affording interesting photovoltaic responses and highlighting a marked potential of PCBtB to tailor the active BHJ layer. The best BHJ solar cells based on as-cast P3HT: PCBtB blend films exhibit power conversion efficiencies (PCEs) of similar to 3.1%, under a simulated AM1.5G illumination of 100 mW cm(-2), which are greater than the analogous as-cast P3HT: PCBM based devices
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