Search results for "optical"

Supramolecular isomerism in spin crossover networks with aurophilic interactions

2004

Assembly of FeII, 3-cyanopyridine and [Au(CN)2]– affords, in one-pot reaction, three coordination polymers that represent a genuine example of supramolecular isomerism with strong influence in the spin crossover regime of the FeII ions. Real Cabezos, Jose Antonio, Jose.A.Real@uv.es

Deposition and production of highly reproducible hybrid Cu[(tBu)4Pc]-polystyrene thin layers via spin casting

2012

This study focuses on the determination of a protocol for the production of a hybrid material composed of a polymer and a macrocyclic complex, namely polystyrene and a tetra-tert-butyl-copper phthalocyanine (Cu[(tBu)4Pc]), in order to obtain a layer thickness of about 100 nm and a controlled porosity in a highly reproducible way. Several methods were implemented and their reproducibility was evaluated through elements of characterization such as optical microscopy, atomic force microscopy and scanning electron microscopy. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers

Evaluation of interfacial shear strength by tensile tests of impregnated flax fiber yarns

2011

Adhesion of flax fibers and polymer matrix as well as mutual bonding of elementary fibers in a technical fiber are among the principal factors governing the mechanical response of flax fiber-reinforced polymer–matrix composites. A method for evaluation of adhesion is proposed based on tension tests of impregnated fiber yarns, with subsequent characterization by optical microscopy of length distribution of fibers pulled out of the yarn fracture surfaces. An elementary probabilistic model is derived relating aspect ratio distribution of the pulled-out fibers to the fiber tensile strength distribution and the effective interfacial shear strength (IFSS). The method was applied to flax fiber/vi…

Combined thermal evaporated and solution processed organic light emitting diodes

2011

Abstract Highly efficient, partly solution processed phosphorescent red, green and white organic light emitting diodes with small molecular weight host materials are prepared from commercially available starting compounds. Starting from an evaporated reference device, layers are stepwise replaced by solution processed layers. Replacing the evaporated hole transport layer by a solution processed polymer interlayer does not affect the performance and allows spincoating of the emissive layer after annealing of the polymer. Devices with, next to the spincoated hole injection and transport layer, a solution processed emission layer show similar characteristics and efficiencies as the reference d…

Optical Field-Induced Mass Transport in Soft Materials

2013

Abstract The dependence of the surface relief formation in amorphous chalcogenide (As 2 S 3 and As-S-Se) and Disperse Red 1 dye grafted polyurethane polymer films on the polarization state of holographic recording light beams was studied. It is shown that the direction of lateral mass transport on the film surface is determined by the direction of light electric vector and photoinduced anisotropy in the film. We propose a photoinduced dielectropfhoretic model to explain the photoinduced mass transport in amorphous films. Model is based on the photoinduced softening of the matrix, formation of defects with enhanced or decreased polarizability, and their drift under the electrical field gradi…

Functional 3D Photonic Films from Polymer Beads

2007

This paper describes synthesis and properties of polymer opals with a special emphasis on functional opals. Polymer opals are formed from monodisperse polymer colloids by self-assembly. Their potential applications range from coloring pigments, 3D bicontinuous supports for catalysis to photonic materials. This latter application requires especially the controlled creation of defects and the incorporation of fluorescent materials. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Efficient photovoltaic and electroluminescent perovskite devices.

2015

Planar diode structures employing hybrid organic–inorganic methylammonium lead iodide perovskites lead to multifunctional devices exhibiting both a high photovoltaic efficiency and good electroluminescence. The electroluminescence strongly improves at higher current density applied using a pulsed driving method.

Dielectric and plasmonic waveguides based on quantum dots embedded in polymers

2013

espanolEn este trabajo se propone una revision de la implementacion de guias de onda activas basadas en la dispersion de puntos cuanticos coloidales (QDs) en polimeros. Para ello, guias de onda planas fueron fabricadas embebiendo distintos tipos de nanoestructuras semiconductoras con emision en el visible e infrarrojo (CdS, CdTe, CdSe, PbS) en PMMA, encontrandose las condiciones optimas para el guiado de su fotoluminiscencia y sus propiedades de ganancia y atenuacion. Si varios tipos de puntos son dispersados en la misma capa se propagan varios colores, siendo posible obtener luz blanca con las proporciones adecuadas de rojo, verde y azul. Asimismo, el guiado puede ser mejorado si una cubie…

Photovoltaic Properties of a Porphyrin-Containing Polymer as Donor in Bulk Heterojunction Solar Cells With Low Energy Loss

2017

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…