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Luminescent Efficiency (luminescent + efficiency)
Selected AbstractsHigh Mobility and Luminescent Efficiency in Organic Single-Crystal Light-Emitting TransistorsADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Satria Zulkarnaen Bisri Abstract A high-performance ambipolar light-emitting transistor (LET) that has high hole and electron mobilities and excellent luminescence characteristics is described. By using this device, a conspicuous light-confined edge emission and current-density-dependent spectral evolution are observed. These findings will result in broader utilization of device potential and they provide a promising route for realizing electrically driven organic lasers. [source] Microwave-Assisted Synthesis of Water-Dispersed CdTe Nanocrystals with High Luminescent Efficiency and Narrow Size Distribution.CHEMINFORM, Issue 18 2007Yao He Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] An Alternative Approach to Constructing Solution Processable Multifunctional Materials: Their Structure, Properties, and Application in High-Performance Organic Light-Emitting DiodesADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Shanghui Ye Abstract A new series of full hydrocarbons, namely 4,4,-(9,9,-(1,3-phenylene)bis(9H -fluorene-9,9-diyl))bis(N,N -diphenylaniline) (DTPAFB), N,N,-(4,4,-(9,9,-(1,3-phenylene)bis(9H -fluorene-9,9-diyl))bis(4,1-phenylene))bis(N -phenylnaphthalen-1-amine) (DNPAFB), 1,3-bis(9-(4-(9H -carbazol-9-yl)phenyl)-9H -fluoren-9-yl)benzene, and 1,3-bis(9-(4-(3,6-di- tert -butyl-9H -carbazol-9-yl)phenyl)-9H -fluoren-9-yl)benzene, featuring a highly twisted tetrahedral conformation, are designed and synthesized. Organic light-emitting diodes (OLEDs) comprising DNPAFB and DTPAFB as hole transporting layers and tris(quinolin-8-yloxy)aluminum as an emitter are made either by vacuum deposition or by solution processing, and show much higher maximum efficiencies than the commonly used N,N,-di(naphthalen-1-yl)- N,N,-diphenylbiphenyl-4,4,-diamine device (3.6 cd A,1) of 7.0 cd A,1 and 6.9 cd A,1, respectively. In addition, the solution processed blue phosphorescent OLEDs employing the synthesized materials as hosts and iridium (III) bis[(4,6-di-fluorophenyl)-pyridinato-N, C2] picolinate (FIrpic) phosphor as an emitter present exciting results. For example, the DTPAFB device exhibits a brightness of 47 902 cd m,2, a maximum luminescent efficiency of 24.3 cd A,1, and a power efficiency of 13.0 lm W,1. These results show that the devices are among the best solution processable blue phosphorescent OLEDs based on small molecules. Moreover, a new approach to constructing solution processable small molecules is proposed based on rigid and bulky fluorene and carbazole moieties combined in a highly twisted configuration, resulting in excellent solubility as well as chemical miscibility, without the need to introduce any solubilizing group such as an alkyl or alkoxy chain. [source] Recent Progress in GaN-Based Light-Emitting DiodesADVANCED MATERIALS, Issue 45 2009Haiqiang Jia Abstract In the last few years the GaN-based white light-emitting diode (LED) has been remarkable as a commercially available solid-state light source. To increase the luminescence power, we studied GaN LED epitaxial materials. First, a special maskless V-grooved c -plane sapphire was fabricated, a GaN lateral epitaxial overgrowth method on this substrate was developed, and consequently GaN films are obtained with low dislocation densities and an increased light-emitting efficiency (because of the enhanced reflection from the V-grooved plane). Furthermore, anomalous tunneling-assisted carrier transfer in an asymmetrically coupled InGaN/GaN quantum well structure was studied. A new quantum well structure using this effect is designed to enhance the luminescent efficiency of the LED to ,72%. Finally, a single-chip phosphor-free white LED is fabricated, a stable white light is emitted for currents from 20 to 60,mA, which makes the LED chip suitable for lighting applications. [source] Design and synthesis of chemiluminescent substrates with high luminescent efficiency in an aqueous system: 5- tert -butyl-4,4-dimethyl-2,6,7-trioxabicyclo[3.2.0]heptanes bearing a 3-hydroxy-4-(1-iminoethyl)phenyl moiety at the 1-positionLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4 2001Masakatsu Matsumoto Abstract A CIEEL-active dioxetane bearing a 4-acetyl-3-hydroxyphenyl moiety has very recently been found to emit light effectively, even in an aqueous system, albeit with a very slow CIEEL decay rate. As an attempt to improve the CIEEL decay rate of this type of dioxetane, three dioxetanes, in which a carbonyl in the 4-acetyl-3-hydroxyphenyl moiety was modified into an oxime, oxime O -methyl ether, or semicarbazone, were synthesized. These three dioxetanes decomposed to emit light far more rapidly than the parent 4-acetyl-3-hydroxyphenyl-substituted dioxetane. Among them, a dioxetane bearing a 3-hydroxy-4-(1-methoxyiminoethyl) phenyl, namely an oxime O -methyl ether derivative, gave high chemiluminescent efficiency. As for a semicarbazone derivative, decrease of the chemiluminescent yield was minimal, even in an aqueous system. Copyright © 2001 John Wiley & Sons, Ltd. [source] | |||||||||||||