Search results for "Toe"
showing 10 items of 3824 documents
Towards Plastic Electronics: Patterning Semiconducting Polymers by Nanoimprint Lithography
2002
The direct patterning of functional semiconducting polymers (see Figure) has been achieved with a nanoimprint lithography technique. The room‐temperature process described is time‐saving as repeated temperature cycling is not required. In addition, due to the direct patterning approach the need for further processing steps (plasma treatment) to pattern the underlying semiconducting material is eliminated.
Spectroscopic Investigations Of LB Mono- And Multilayers Of 2-docosylamino 5-nitropyridine; Promising Candidates For Non-linear And Integrated Optics
2005
Alkylamino-5-nitropyridineshavemently been introduced forthepreparation of a novel type of non-centrosymmetric Langmuir-Blodgett (LB) multilayer (1,2). Hitherto, second order non-linear optical investigations have been resmcted toLB-films oftwomaterialsinaltematinglayerstructureand to films of a single material with head to tail arrangement of the molecules, both of whicharedifficulttoobtain (seerefs. quotedin 1 and2.1. Incontrast,allpresent data indicate that LB-filmsof 2-aUcylamino-5-nitropyridines are head-to-head and tail-to-tail (Y-type) multilayers with a rather strong tilt-angle of the alkyl chains (Fig. I). The most effective substance for second order non-linear optical experiments…
Photovoltaic Properties of a Porphyrin-Containing Polymer as Donor in Bulk Heterojunction Solar Cells With Low Energy Loss
2017
Poling dynamics of an EO active material using parallel-plate electrodes
2017
We describe the sample preparation and experimental setup for second harmonic generation measurement of electro-optical (EO) chromophore/polymer system at the time of contact-poling. Different types of spacers for avoiding electric breakdown due to avalanche multiplication are compared. Electric field threshold values for second harmonic generation are observed in all samples.
Novel benzofulvenes-based polymers: Characterization and employment in flexible electrochromic devices
2014
Benzofulvenes-based monomers have been synthesized for the first time and have been polymerized by means of electrochemical methods onto different electrodic materials. Morphological investigation has been performed by using SEM; electrical and optical properties have been studied by means of both cyclic voltammetry, optical absorption and spectroelectrochemical techniques. Finally, solid state electrochromic devices have been fabricated. They have displayed high optical contrast.
Ionically Assisted Charge Injection in Hybrid Organic−Inorganic Light-Emitting Diodes
2010
We have developed hybrid organic−inorganic light-emitting diodes (HyLEDs) featuring a buffer layer of a conjugated polyelectrolyte (CPE) sandwiched between a light emitting polymer (LEP) film and a ZnO electron injection layer. Efficacies exceeding 5 cd/A and the possibility of employing various LEPs are demonstrated. These improvements, compared to HyLEDs without any interlayer, are attributed to the redistribution of ions in the CPE film, causing hole accumulation at the CPE/LEP interfaces and enhanced electron injection from the ZnO into the electroluminescent polymer. The intrinsic air-stability of the electrodes used in HyLEDs, together with the solution processability of the ZnO/CPE/L…
Economical device for measuring thickness of a thin polymer film
1994
An inexpensive device (about $2K) for thickness measurements of thin (<1 μm) polymer films has been constructed. The homogeneous film is placed on a bulk substrate and three semiconductor lasers of different wavelengths are used to measure the reflectances at normal incidence. The thickness can be deduced with typically 4–8 nm uncertainty.
Synthesis and Characterization of the Hybrid Clay-Based Material Montmorillonite-Melanoidin: A Potential Soil Model
2010
The study of the interactions among metals, minerals, and humic substances is essential in understanding the migration of inorganic pollutants in the geosphere. A considerable amount of organic matter in the environment is associated with clay minerals. To understand the role of organic matter in the environment and its association with clay minerals, a hybrid clay-based material (HCM), montmorillonite (STx-1)-melanoidin, was prepared from L-tyrosine and L-glutamic acid by the Maillard reaction. The HCM was characterized by elemental analysis, nuclear magnetic resonance, x-ray photoelectron spectroscopy (XPS), scanning transmission x-ray microscopy (STXM), and thermal analysis. The presence…
<title>Holographic recording in polymer composites of organic photochromes and chalcogenides</title>
2008
Recently a number of organic and inorganic materials have been studied for direct surface-relief formation during the exposure process by a light or e-beam. It is very promising for practical application enabling the possibility to simplify the surface-relief formation technology. In this report the method of preparation of thin polymer-chalcogenide and polymer-azobenzene composite films is described, and some features of photoinduced changes of optical properties and holographic recording of these materials are studied. Films of composites were obtained from solution of arsenic sulphide, Disperse red 1 and polymers in organic solvents. The solution was spread on glass substrate and dried. …
Photoluminescence waveguiding in CdSe and CdTe QDs–PMMA nanocomposite films
2011
In this paper, active planar waveguides based on the incorporation of CdSe and CdTe nanocrystal quantum dots in a polymer matrix are demonstrated. In the case of doping the polymer with both types of quantum dots, the nanocomposite film guides both emitted colors, green (550 nm, CdTe) and orange (600 nm, CdSe). The optical pumping laser can be coupled not only with a standard end-fire coupling system, but also directing the beam to the surface of the sample, indicating a good absorption cross-section and waveguide properties. To achieve these results, a study of the nanocomposite optical properties as a function of the nanocrystal concentration is presented and the optimum conditions are fo…