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White-Light Emission (white-light + emission)

Distribution by Scientific Domains

Polymers and Materials Science	84%

Selected Abstracts

Tunable Emission from Binary Organic One-Dimensional Nanomaterials: an Alternative Approach to White-Light Emission

ADVANCED MATERIALS, Issue 7 2008
Yong Sheng Zhao
No abstract is available for this article. [source]

Tunable Emission from Binary Organic One-Dimensional Nanomaterials: An Alternative Approach to White-Light Emission,

ADVANCED MATERIALS, Issue 1 2008
S. Zhao
Uniformly doped crystalline organic nanorods and nanowires are prepared by adsorbent-assisted physical vapor deposition. The emission color of the binary 1D nanomaterials can be controlled , and made to approach white light (see figure) , by changing the doping content, which is ascribed to intermolecular fluorescence resonance energy transfer between the two nanocrystalline components. [source]

High-Efficiency White-Light Emission from a Single Copolymer: Fluorescent Blue, Green, and Red Chromophores on a Conjugated Polymer Backbone,

ADVANCED MATERIALS, Issue 8 2007
J. Luo
The synthesis and properties of a single copolymer incorporating well-separated blue, green, and red chromophores on a single conjugated polymer backbone are reported. This copolymer is shown to have CIE coordinates of (0.35,0.34) and a luminance efficiency of 6.2,cd,A,1. The color coordinates of the resulting white-light emission remained extremely stable over a wide range of driving voltages. [source]

Cover Picture: Multilayer Polymer Light-Emitting Diodes: White-Light Emission with High Efficiency (Adv. Mater.

ADVANCED MATERIALS, Issue 17 2005
17/2005)
Abstract White-light-emitting polymer diodes can be fabricated by solution processing using a blend of luminescent semiconducting polymers and organometallic complexes as the emission layer, and water-soluble (or ethanol-soluble) polymers and/or small molecules as the hole-injection/transport layer (HIL/HTL) and the electron injection/transport layer (EIL/ETL), as reported on p.,2053 by Gong, Bazan, Heeger and co-workers. Illumination-quality light is obtained from these multilayer, high-performance devices, with stable CIE coordinates, color temperatures, and high color-rendering indices all close to those of "pure" white light. The cover illustration envisages the incorporation of the fabrication technique with low-cost manufacturing technology in order to produce large areas of high-quality white light. [source]

White-Light Emission from a Single-Emitting-Component Organic Electroluminescent Device,

ADVANCED MATERIALS, Issue 17 2004
Y. Li
Three-layer electroluminescent devices fabricated from 1,3,5-tris(2-(9-ethylcarbazyl-3)ethylene) benzene (TECEB) (see Figure) are shown to exhibit bright and efficient white light with a maximum luminescence and current efficiency of 1200,cd,m,2 and 1.1,cd,A,1, respectively. It is suggested that these represent the best reported results for single-emitting-component white electroluminescent devices to date. [source]

White-Light Emission from a Single Polymer with Singlet and Triplet Chromophores on the Backbone

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 24 2006
Hongyu Zhen
Abstract Summary: A strategy to generate an efficient white-light emission has been developed by mixing fluorescence and phosphorescence emission from a single polymer. Fluorene is used as the blue-emissive component, benzothiadiazole (BT) and the iridium complex [(btp)2Ir(tmd)] are incorporated into a polyfluorene backbone, respectively, as green- and red-emissive chromophores by Suzuki polycondensation. By changing the contents of BT and [(btp)2Ir(tmd)] in the polymer, the electroluminescence spectrum from a single polymer can be adjusted to achieve white-light emission. A white polymeric light-emitting diode (WPLED) with a structure of ITO/PEDOT:PSS/PVK/PFIrR1G03/CsF/Al shows a maximum external quantum efficiency of 3.7% and the maximum luminous efficiency of 3.9 cd,·,A,1 at the current density of 1.6 mA,·,cm,2 with the CIE coordinates of (0.33, 0.34). The maximum luminance of 4,180 cd,·,m,2 is achieved at the current density of 268 mA,·,cm,2 with the CIE coordinates of (0.31, 0.32). The white-light emissions from such polymers are stable in the white-light region at all applied voltages, and the electroluminescence efficiencies decline slightly with the increasing current density, thus indicating that the approach of incorporating singlet and triplet species into the polymer backbone is promising for WPLEDs. Structure of PFIrR1G04 and the EL spectra of its devices under various voltages. Device structure: ITO/PEDOT:PSS/PVK/polymer/CsF/Al. [source]

Synthesis, Photophysical, and Electroluminescent Device Properties of Zn(II)-Chelated Complexes Based on Functionalized Benzothiazole Derivatives

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2009
Soo-Gyun Roh
Abstract New Zn(II)-chelated complexes based on benzothiazole derivatives, including substituted functional groups such as methyl (MeZn), methoxy (MeOZn), or fluorenyl unit (FuZn), are investigated to produce white-light emission. 2-(2-Hydroxyphenyl)benzothiazole derivatives in toluene and DMSO exhibit excited-state intramolecular proton transfer (ESIPT), leading to a large Stokes shift of the fluorescence emission. However, in methanol they exhibit no ESIPT due to the intermolecular hydrogen bonding between the 2-(2-hydroxyphenyl)benzothiazole derivative and methanol. Their Zn(II)-chelated complexes exhibit the absorption band red-shifted at 500,nm in nonpolar solvent and the absorption band blue-shifted at about 420,nm in protic solvent. In multilayer electroluminescent devices, methyl-substituted Zn(II)-chelated complex (MeZn) exhibits excellent power efficiency and fluorene-substituted Zn(II)-chelated complex (FuZn) has a high luminance efficiency (1,cd,m,2 at 3.5,V, 10,400,cd,m,2 at 14,V). The EL spectra of Zn(II)-chelated complexes based on benzothiazole derivatives exhibit broad emission bands. In addition, their electron-transport property for red,green,blue (RGB) organic light-emitting diodes (OLEDs) is systematically studied, in comparison with that of Alq3. The results demonstrate the promising potential of MeZn as an electron-transporting layer (ETL) material in preference to Alq3, which is widely used as an ETL material. [source]

Efficient Visible-Light Emission from Dye-Doped Mesostructured Organosilica

ADVANCED MATERIALS, Issue 47 2009
Norihiro Mizoshita
Efficient and color-tunable visible-light emission is achieved in fluorescent dye-doped oligo(phenylenevinylene),silica mesostructured films through fluorescence resonance energy transfer from a blue-light-emitting organosilica to a yellow-light-emitting dye (see figure). Tuning of the composition realizes pseudo white-light emission with a quantum yield of 67%. Utilization of both walls and pores of the mesostructured organosilicas is effective to construct highly functional systems. [source]

High-Efficiency White-Light Emission from a Single Copolymer: Fluorescent Blue, Green, and Red Chromophores on a Conjugated Polymer Backbone,

White-Light Emission from a Single Polymer with Singlet and Triplet Chromophores on the Backbone

High resolution observations of white-light emissions from the opacity minimum during an X-class flare

ASTRONOMISCHE NACHRICHTEN, Issue 6 2010
Y. Xu
Abstract Using high cadence, high resolution near infrared (NIR) observations of the X10 white-light flare (WLF) on 2003 October 29, we investigated the evolution of the core-halo structure of white-light emission during the two-second period flare peak. We found that size and intensity of the halo remained almost constant in the range of 10 Mm2. However, the core area was very compact and expanded rapidly from about 1 Mm2 to 4 Mm2. At the same time, the total emission of the core increased nearly twenty times. This distinct behavior indicates that different heating mechanisms might be responsible for core and halo emissions. In addition to the temporal analysis, we compared the intensity enhancements of the flare core and halo. The result shows that the halo contrast increased by about 8% compared to the flare-quiet region, which could be explained by a combination of direct-heating and backwarming models (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]