Search results for "Optoelectronics"

showing 10 items of 2306 documents

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.

chemistry.chemical_classificationMaterials sciencebusiness.industryPolingElectrical breakdownNonlinear opticsSecond-harmonic generation02 engineering and technologyPolymerChromophore021001 nanoscience & nanotechnology01 natural sciences010309 opticschemistryElectric field0103 physical sciencesElectrodeOptoelectronics0210 nano-technologybusinessSPIE Proceedings
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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.

chemistry.chemical_classificationMaterials sciencebusiness.industryPolymerElectrochromic devicesElectrochemistryCharacterization (materials science)electrochromic materialschemistry.chemical_compoundMonomerPolymerizationchemistryElectrochromic DeviceOptoelectronicsCyclic voltammetryAbsorption (electromagnetic radiation)businessBenzofulvenesSettore CHIM/02 - Chimica Fisica2014 16th International Conference on Transparent Optical Networks (ICTON)
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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…

chemistry.chemical_classificationMaterials sciencebusiness.industryPolymerElectroluminescenceBuffer (optical fiber)Ionlaw.inventionchemistrylawElectrodeOLEDOptoelectronicsGeneral Materials SciencebusinessDiodeLight-emitting diodeACS Applied Materials & Interfaces
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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.

chemistry.chemical_classificationMaterials sciencebusiness.industryPolymerSubstrate (electronics)Semiconductor laser theoryOptical reflectionWavelengthCarbon filmchemistryHomogeneousOptoelectronicsThin filmbusinessInstrumentationReview of Scientific Instruments
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&lt;title&gt;Holographic recording in polymer composites of organic photochromes and chalcogenides&lt;/title&gt;

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. …

chemistry.chemical_classificationMicroscopeMaterials scienceHolographic gratingbusiness.industryChalcogenideHolographyPolymerDiffraction efficiencyMicroanalysislaw.inventionchemistry.chemical_compoundOpticschemistrylawOptoelectronicsbusinessDiffraction gratingSPIE Proceedings
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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…

chemistry.chemical_classificationNanocompositePhotoluminescenceMaterials scienceCondensed Matter::Otherbusiness.industryMechanical EngineeringDopingPhysics::OpticsBioengineeringGeneral ChemistryPolymerCondensed Matter::Mesoscopic Systems and Quantum Hall EffectCadmium telluride photovoltaicsOptical pumpingCondensed Matter::Materials ScienceNanocrystalchemistryMechanics of MaterialsQuantum dotOptoelectronicsGeneral Materials ScienceElectrical and Electronic EngineeringbusinessNanotechnology
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Dielectrophoresis as a tool for nanoscale DNA manipulation

2005

The use of the dielectrophoresis as a tool for DNA manipulation is demonstrated experimentally, using both unmodified 48,500 base pairs long bacteriophage lambda dsDNA (λ-DNA), ∼16 μm in length and 414 base pairs long thiol modified natural dsDNA (avDNA), ∼140 nm in length. We show that both the dsDNA types used, are effectively directed between the planar gold electrodes by the positive dielectrophoresis while applying an AC voltage at frequencies between 500 kHz and 1 MHz. With high concentrations of dsDNA in buffer the attached dsDNA molecules are shown to form bundles or clumps (both λ-DNA and avDNA). Furthermore, we demonstrate the attaching of a single avDNA molecule to an electrode v…

chemistry.chemical_classificationNanostructurebusiness.industryBase pairBiomoleculeAnalytical chemistryBioengineeringDielectrophoresisCondensed Matter PhysicschemistryOptical tweezersElectric fieldElectrodeMaterials ChemistryOptoelectronicsElectrical and Electronic EngineeringbusinessNanoscopic scale
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Chalcogenide Fibers for Mid-IR Light Generation: Potentialities and Drawbacks of the Microstructured Design in Sulfide Waveguides

2014

We study optical and structural aging in As2S3 microstructured optical fibers, submitted to room atmosphere that may have, among others, an impact on mid-infrared supercontinuum generation.

chemistry.chemical_classificationPHOSFOSOptical fiberMaterials scienceSulfidebusiness.industryChalcogenideMicrostructured optical fiberlaw.inventionSupercontinuumchemistry.chemical_compoundOpticsZero-dispersion wavelengthchemistrylawOptoelectronicsbusinessPhotonic-crystal fiberAdvanced Solid State Lasers
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Insight in NLO Polymer Material Behavior from Langevin Dynamic Modeling of Chromophore Poling

2011

Calculation of chromophore polar order, i.e. the polarization of nonlinear optically (NLO) active polymers poled by external field, is challenging. One possible solution is to reproduce the orientation polarization of chromophores under external field using Langevin dynamics (LD) molecular modeling. The present work investigates the influence of chromophore dipole moment, density and field extent on NLO efficiency and polarization/relaxation dynamics. Results of simulations convince us, that the method is applicable for modeling real NLO polymers. In the spotlight of this investigation we would like to describe a NLO polymer as a “ferrofluid” where chromophores are active particles or elect…

chemistry.chemical_classificationQuantitative Biology::BiomoleculesFerrofluidMaterials sciencebusiness.industryPolingPolymerChromophoreCondensed Matter PhysicsPolarization (waves)Electronic Optical and Magnetic MaterialsDipolechemistryControl and Systems EngineeringChemical physicsMaterials ChemistryCeramics and CompositesOptoelectronicsHigh Energy Physics::ExperimentElectretPhysics::Chemical PhysicsElectrical and Electronic EngineeringLangevin dynamicsbusinessIntegrated Ferroelectrics
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Strontium Insertion in Methylammonium Lead Iodide: Long Charge Carrier Lifetime and High Fill-Factor Solar Cells.

2016

The addition of Sr2+ in CH3 NH3 PbI3 perovskite films enhances the charge carrier collection efficiency of solar cells leading to very high fill factors, up to 85%. The charge carrier lifetime of Sr2+ -containing perovskites is in excess of 40 μs, longer than those reported for perovskite single crystals.

chemistry.chemical_classificationStrontiumMaterials sciencebusiness.industryMechanical EngineeringInorganic chemistryIodideDopingchemistry.chemical_element02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical scienceschemistryMechanics of MaterialsOptoelectronicsGeneral Materials ScienceFill factorCharge carrier0210 nano-technologybusinessPerovskite (structure)Advanced materials (Deerfield Beach, Fla.)
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