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Device Architectures (device + architecture)
Selected AbstractsPolymer Photovoltaics with Alternating Copolymer/Fullerene Blends and Novel Device ArchitecturesADVANCED MATERIALS, Issue 20 2010Olle Inganäs Abstract The synthesis of novel conjugated polymers, designed for the purpose of photovoltaic energy conversion, and their properties in polymer/fullerene materials and photovoltaic devices are reviewed. Two families of main-chain polymer donors, based on fluorene or phenylene and donor,acceptor,donor comonomers in alternating copolymers, are used to absorb the high-energy parts of the solar spectrum and to give high photovoltages in combinations with fullerene acceptors in devices. These materials are used in alternative photovoltaic device geometries with enhanced light incoupling to collect larger photocurrents or to enable tandem devices and enhance photovoltage. [source] Diagnostic Implications of Uric Acid in Electroanalytical MeasurementsELECTROANALYSIS, Issue 14 2005Abstract Urate has a long history in clinical analysis and has served as an important diagnostic in a number of contexts. The increasing interest in metabolic syndrome has led to urate being used in combination with a number of other biomarkers in the assessment of cardiovascular risk. The traditional view of urate as principally an interferent in electrochemical measurement is now gradually being replaced with the realization that its measurement could serve as an invaluable secondary (if not primary) marker when monitoring conditions such as diabetes and heart disease. Rather than attempting to wholly exclude urate electrochemistry, many strategies are being developed that can integrate the urate signal within the device architecture such that a range of biomarkers can be sequentially assessed. The present review has sought to rationalize the clinical importance that urate measurements could hold in future diagnostic applications , particularly within near patient testing contexts. The technologies harnessed for its detection and also those previously employed for its removal are reviewed with the aim of highlighting how the seemingly contrasting approaches are evolving to aid the development of new sensing devices for clinical analysis. [source] GPU-accelerated boundary element method for Helmholtz' equation in three dimensionsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 10 2009Toru Takahashi Abstract Recently, the application of graphics processing units (GPUs) to scientific computations is attracting a great deal of attention, because GPUs are getting faster and more programmable. In particular, NVIDIA's GPUs called compute unified device architecture enable highly mutlithreaded parallel computing for non-graphic applications. This paper proposes a novel way to accelerate the boundary element method (BEM) for three-dimensional Helmholtz' equation using CUDA. Adopting the techniques for the data caching and the double,single precision floating-point arithmetic, we implemented a GPU-accelerated BEM program for GeForce 8-series GPUs. The program performed 6,23 times faster than a normal BEM program, which was optimized for an Intel's quad-core CPU, for a series of boundary value problems with 8000,128000 unknowns, and it sustained a performance of 167,Gflop/s for the largest problem (1 058 000 unknowns). The accuracy of our BEM program was almost the same as that of the regular BEM program using the double precision floating-point arithmetic. In addition, our BEM was applicable to solve realistic problems. In conclusion, the present GPU-accelerated BEM works rapidly and precisely for solving large-scale boundary value problems for Helmholtz' equation. Copyright © 2009 John Wiley & Sons, Ltd. [source] Multilevel fast multipole algorithm enhanced by GPU parallel technique for electromagnetic scattering problemsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2010Kan Xu Abstract Along with the development of graphics processing Units (GPUS) in floating point operations and programmability, GPU has increasingly become an attractive alternative to the central processing unit (CPU) for some of compute-intensive and parallel tasks. In this article, the multilevel fast multipole algorithm (MLFMA) combined with graphics hardware acceleration technique is applied to analyze electromagnetic scattering from complex target. Although it is possible to perform scattering simulation of electrically large targets on a personal computer (PC) through the MLFMA, a large CPU time is required for the execution of aggregation, translation, and deaggregation operations. Thus GPU computing technique is used for the parallel processing of MLFMA and a significant speedup of matrix vector product (MVP) can be observed. Following the programming model of compute unified device architecture (CUDA), several kernel functions characterized by the single instruction multiple data (SIMD) mode are abstracted from components of the MLFMA and executed by multiple processors of the GPU. Numerical results demonstrate the efficiency of GPU accelerating technique for the MLFMA. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 502,507, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24963 [source] Measuring carrier mobility in conventional multilayer organic light emitting devices by delayed exciton generationPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2008S. Reineke Abstract The authors present an alternative method for the determination of the charge carrier mobility of organic thin films. In contrast to known methods like space charge limited current, field effect transistor and time of flight approaches, we determine the charge carrier mobility of a mixed film, serving as emission layer, within the conventional multilayer device architecture. We make use of a strong delayed generation feature in the electroluminescent decay, following a short voltage pump pulse in a time-resolved set-up. Taking into account the preferentially electron transporting properties of the film, the mobility of a N,N ,-di(naphthalen-2-yl)- N,N ,-diphenyl-benzidine (NPB):tris(1-phenylisoquinoline) iridium [Ir(piq)3] mixed film is found to be on the order of 10,5 cm2 (Vs),1. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Conjugated-Polymer-Based Lateral Heterostructures Defined by High-Resolution PhotolithographyADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Jui-Fen Chang Abstract Solution processing of polymer semiconductors provides a new paradigm for large-area electronics manufacturing on flexible substrates, but it also severely restricts the realization of interesting advanced device architectures, such as lateral heterostructures with defined interfaces, which are easily accessible with inorganic materials using photolithography. This is because polymer semiconductors degrade, swell, or dissolve during conventional photoresist processing. Here a versatile, high-resolution photolithographic method is demonstrated for patterning of polymer semiconductors and exemplify this with high-performance p-type and n-type field-effect transistors (FETs) in both bottom- and top-gate architectures, as well as ambipolar light-emitting field-effect transistors (LEFETs), in which the recombination zone can be pinned at a photolithographically defined lateral heterojunction between two semiconducting polymers. The technique therefore enables the realization of a broad range of novel device architectures while retaining optimum materials performance. [source] Cover Picture: Fabrication of Stable Metallic Patterns Embedded in Poly(dimethylsiloxane) and Model Applications in Non-Planar Electronic and Lab-on-a-Chip Device Patterning (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 4 2005Mater. Abstract A composite image is shown that highlights examples of device architectures that either incorporate or exploit polymer-embedded metallic microstructures. In work reported by Nuzzo and co-workers on p.,557, new applications of soft lithography, in conjunction with advanced forms of multilayer metallization, are used to construct these exceptionally durable structures. They are suitable for use in non-planar lithographic patterning, and as device components finding applications ranging from microelectronics to Lab-on-a-Chip analytical systems. This article describes the fabrication of durable metallic patterns that are embedded in poly(dimethylsiloxane) (PDMS) and demonstrates their use in several representative applications. The method involves the transfer and subsequent embedding of micrometer-scale gold (and other thin-film material) patterns into PDMS via adhesion chemistries mediated by silane coupling agents. We demonstrate the process as a suitable method for patterning stable functional metallization structures on PDMS, ones with limiting feature sizes less than 5,,m, and their subsequent utilization as structures suitable for use in applications ranging from soft-lithographic patterning, non-planar electronics, and microfluidic (lab-on-a-chip, LOC) analytical systems. We demonstrate specifically that metal patterns embedded in both planar and spherically curved PDMS substrates can be used as compliant contact photomasks for conventional photolithographic processes. The non-planar photomask fabricated with this technique has the same surface shape as the substrate, and thus facilitates the registration of structures in multilevel devices. This quality was specifically tested in a model demonstration in which an array of one hundred metal oxide semiconductor field-effect transistor (MOSFET) devices was fabricated on a spherically curved Si single-crystalline lens. The most significant opportunities for the processes reported here, however, appear to reside in applications in analytical chemistry that exploit devices fabricated using the methods of soft lithography. Toward this end, we demonstrate durably bonded metal patterns on PDMS that are appropriate for use in microfluidic, microanalytical, and microelectromechanical systems. We describe a multilayer metal-electrode fabrication scheme (multilaminate metal,insulator,metal (MIM) structures that substantially enhance performance and stability) and use it to enable the construction of PDMS LOC devices using electrochemical detection. A polymer-based microelectrochemical analytical system, one incorporating an electrode array for cyclic voltammetry and a microfluidic system for the electrophoretic separation of dopamine and catechol with amperometric detection, is demonstrated. [source] Recent Advances in White Organic Light-Emitting Materials and Devices (WOLEDs)ADVANCED MATERIALS, Issue 5 2010Kiran T. Kamtekar Abstract WOLEDs offer new design opportunities in practical solid-state lighting and could play a significant role in reducing global energy consumption. Obtaining white light from organic LEDs is a considerable challenge. Alongside the development of new materials with improved color stability and balanced charge transport properties, major issues involve the fabrication of large-area devices and the development of low-cost manufacturing technology. This Review will describe the types of materials (small molecules and polymers) that have been used to fabricate WOLEDs. A range of device architectures are presented and appraised. [source] Carbon-Based Field-Effect Transistors for NanoelectronicsADVANCED MATERIALS, Issue 25-26 2009Marko Burghard Abstract In this review, the suitability of the major types of carbon nanostructures as conducting channels of field-effect transistors (FETs) is compared on the basis of the dimensionality and size of their ,-conjugated system. For each of these materials, recent progress in its synthesis, electrical and structural characterization, as well as its implementation into various gate configurations is surveyed, with emphasis laid onto nanoscale aspects of the FET design and the attainable device performance. Finally, promising future research directions, such as the integration of different carbon nanostructures into novel device architectures, are outlined. [source] Self-Assembly: Molecular Self-Assembled Monolayers and Multilayers for Organic and Unconventional Inorganic Thin-Film Transistor Applications (Adv. Mater.ADVANCED MATERIALS, Issue 14-15 200915/2009) A self-assembled monolayer (SAM) of azo stillbazolium sandwiched between two conductive electrodes is shown. The upper and lower electrodes are doped silicon and a Hg drop, respectively, a configuration often used for measuring the conductivity of SAMs and multilayers of hybrid organic and inorganic materials. The evaluation and implementation of these unconventional materials in complex device architectures is highlighted in the review on page 1407 by Sara DiBenedetto et al. [source] | |||||||||||||