Home  About us  Contact
 

Color Purity (color + purity)

Distribution by Scientific Domains
Polymers and Materials Science83%

Selected Abstracts

Pure and Saturated Red Electroluminescent Polyfluorenes with Dopant/Host System and PLED Efficiency/Color Purity Trade-Offs

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Lei Chen
Abstract Three kinds of red electroluminescent (EL) polymers based on polyfluorene as blue host and 2,1,3-benzothiadiazole derivatives with different emission wavelengths as red dopant units on the side chain are designed and synthesized. The influence of the photoluminescence (PL) efficiencies and emission wavelengths of red dopants on the EL efficiencies and color purities of the resulting polyfluorene copolymers of dopant/host system is investigated by adjusting the electron donating ability of the donor units in D- , -A-D typed 2,1,3-benzothiadiazole derivatives. The devices of these red-emitting polymers realize remarkable EL efficiency/color purity trade-offs. The single-layer devices with the configuration of ITO/PEDOT:PSS/Polymer/Ca/Al show pure red emission at 624 nm with a luminous efficiency of 3.83 cd A,1 and CIE of (0.63, 0.35) for PFR1, saturated red emission at 636 nm with a luminous efficiency of 2.29 cd A,1 and CIE of (0.64, 0.33) for PFR2, respectively. By introduction of an additional electron injection layer PF-EP(Ethanol soluble phosphonate-functionalized polyfluorene), high performance pure and saturated red emission two-layer devices (ITO/PEDOT:PSS/Polymer/PF-EP/LiF/Al) were achieved with maximum luminous efficiencies of 5.50 cd A,1 and CIE of (0.62, 0.35) for PFR1, 3.10 cd A,1 and CIE of (0.63, 0.33) for PFR2, respectively, which are the best results for pure and saturated fluorescent red EL polymers reported so far. [source]

Phosphorescent OLEDs: Synthesis and Characterization of Red-Emitting Iridium(III) Complexes for Solution-Processable Phosphorescent Organic Light-Emitting Diodes (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2009
Mater.
On page 2205, S.H. Jin and co-workers report on the development of red-emitting iridium(III) complexes for solution-processable phosphorescent organic light-emitting diodes (PhOLEDs). This frontispiece image shows the fabrication of full-color PhOLEDs by an inkjet printing method. The combination of good efficiency and color purity identifies this material as a promising candidate for red phosphorescent doping of PhOLEDs. Structure-property relationships for improving the performance of such devices are also investigated. [source]

Synthesis and Characterization of Red-Emitting Iridium(III) Complexes for Solution-Processable Phosphorescent Organic Light-Emitting Diodes

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2009
Seung-Joon Lee
Abstract A new series of highly efficient red-emitting phosphorescent Ir(III) complexes, (Et-CVz-PhQ)2Ir(pic-N-O), (Et-CVz-PhQ)2Ir(pic), (Et-CVz-PhQ)2Ir(acac), (EO-CVz-PhQ)2Ir(pic-N-O), (EO-CVz-PhQ)2Ir(pic), and (EO-CVz-PhQ)2Ir(acac), based on carbazole (CVz)-phenylquinoline (PhQ) main ligands and picolinic acid N-oxide (pic-N-O), picolinic acid (pic), and acetylacetone (acac) ancillary ligands, are synthesized for phosphorescent organic light-emitting diodes (PhOLEDs), and their photophysical, electrochemical, and electroluminescent (EL) properties are investigated. All of the Ir(III) complexes have high thermal stability and emit an intense red light with an excellent color purity at CIE coordinates of (0.65,0.34). Remarkably, high-performance solution-processable PhOLEDs were fabricated using Ir(III) complexes with a pic-N-O ancillary ligand with a maximum external quantum efficiency (5.53%) and luminance efficiency (8.89,cd,A,1). The novel use of pic-N-O ancillary ligand in the synthesis of phosphorescent materials is reported. The performance of PhOLEDs using these Ir(III) complexes correlates well with the results of density functional theory calculations. [source]

Luminescent Soft Material: Two New Europium-Based Ionic Liquids

HELVETICA CHIMICA ACTA, Issue 11 2009
Sifu Tang
Abstract Two new Eu-based ionic liquid systems, [C4mim][DTSA],:,[Eu(DTSA)3] and 2[C4mim] [DTSA],:,[Eu(DTSA)3] were synthesized at 120° under inert conditions from 1-butyl-1-methylimidazolium ditoluenesulfonylamide ([C4mim][DTSA]). The identity and purity of the synthesized compounds were confirmed by elemental analysis, IR, Raman, and 1H-NMR spectroscopy. As they solidify below 100° as glasses they qualify as ionic liquids. Fluorescence measurements show that the materials exhibit a strong red luminescence of high color purity. Therefore, they have the potential to be used for optical applications such as in emission displays. [source]

Rapid Synthesis of Non-Aggregated Fine Chloroapatite Blue Phosphor Powders with High Quantum Efficiency,

ADVANCED MATERIALS, Issue 18 2008
Wei-Ning Wang
Sub-micrometer-sized chloroapatite blue phosphors are successfully synthesized from aqueous precursors using a spray pyrolysis method with a very short processing time and without any post-heat treatments. The as-prepared phosphors reveal high quantum efficiency in the long-UV range (around 80% under excitation at 400,nm), spherical morphology, high crystallinity, and high color purity, showing great promise for white LED applications. [source]

Emission Colour Tuning in Semiconducting Polymer Nanotubes by Energy Transfer to Organo- Lanthanide Dopants,

ADVANCED MATERIALS, Issue 18 2007
S. Moynihan
Tuning of emission chromaticity in poly(N -vinylcarbazole) nanotubes by efficient energy transfer to luminescent Eu(dbm)3(Phen) organo-lanthanide chelate dopants is demonstrated. Nanotubes are synthesized by solution assisted template wetting. Under optical excitation, undoped tubes luminesce in the blue while doped tubes exhibit red europium ion emission with good color purity at the single nanotube level. [source]