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Single-layer Device (single-layer + device)
Selected AbstractsA Series of Red-Light-Emitting Ionic Iridium Complexes: Structures, Excited State Properties, and Application in Electroluminescent DevicesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2008Shu-Juan Liu Abstract A series of ionic diiminoiridium complexes [Ir(piq-C,N)2(L-N,N)](PF6) were prepared, where piq-C,N is 1-phenylisoquinolinato and L-N,N are bidentate N-coordinating ligands: 2,2,-bipyridine (bpy), 4,4,-dimethyl-2,2,-bipyridine (mbpym), 5,5,-bis(thiopen-2-yl)-2,2,-bipyridine (tbpyt), and 5,5,-bis(9,9-dioctylfluoren-2-yl)-2,2,-bipyridine (FbpyF). X-ray diffraction studies of [Ir(piq)2(mbpym)](PF6) revealed that the iridium center adopts a distorted octahedral geometry. All complexes exhibited intense and long-lived emission at room temperature. The substituents on the 2,2,-bipyridine moieties influence the photophysical and electrochemical properties. The excited states were investigated through theoretical calculations together with photophysical and electrochemical properties. It was found that the excited state of the [Ir(piq)2(FbpyF)](PF6) complex can be assigned to a mixed character of 3LC (,N,N,,*N,N), 3MLCT, 3LLCT (,C,N,,*N,N), and 3LC (,C,N,,*C,N). In addition, the alkylfluorene-substituted complex, [Ir(piq)2(FbpyF)](PF6), hadrelatively high quantum efficiency and good film-forming ability, and it was expected to be a good candidate for lighting and display applications. A nondoped, single-layer device that incorporates this complex as a light-emitting layer was fabricated and red phosphorescence was obtained.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Stable, Glassy, and Versatile Binaphthalene Derivatives Capable of Efficient Hole Transport, Hosting, and Deep-Blue Light EmissionADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Bin Wei Abstract Organic light-emitting diodes (OLEDs) have great potential applications in display and solid-state lighting. Stability, cost, and blue emission are key issues governing the future of OLEDs. The synthesis and photoelectronics of a series of three kinds of binaphthyl (BN) derivatives are reported. BN1,3 are "melting-point-less" and highly stable materials, forming very good, amorphous, glass-like films. They decompose at temperatures as high as 485,545,°C. At a constant current density of 25,mA,cm,2, an ITO/BN3/Al single-layer device has a much-longer lifetime (>80,h) than that of an ITO/NPB/Al single-layer device (8,h). Also, the lifetime of a multilayer device based on BN1 is longer than a similar device based on NPB. BNs are efficient and versatile OLED materials: they can be used as a hole-transport layer (HTL), a host, and a deep-blue-light-emitting material. This versatility may cut the cost of large-scale material manufacture. More importantly, the deep-blue electroluminescence (emission peak at 444 nm with CIE coordinates (0.16, 0.11), 3.23 cd A,1 at 0.21,mA cm,2, and 25200,cd,m,2 at 9,V) remains very stable at very high current densities up to 1000,mA,cm,2. [source] Synthesis of a novel luminescent copolymer based on bisphenol APOLYMER INTERNATIONAL, Issue 9 2005Hager Trad Abstract A new luminescent copolymer (BPAEt2 -BP; Scheme 1), with short alternating divinylbiphenyl units and O -diethylated bisphenol A (BPAEt2), was synthesized via the Wittig reaction. The polymer is fully soluble in common organic solvents and has a number-average molecular weight of 4600 g mol,1 with a polydispersity index of 1.79. The structure of the polymer was confirmed by 1H NMR, 13C NMR, FTIR and Raman analysis. Thermal analysis of the polymer showed good stability up to 280 °C. Furthermore, polymer film absorbs at 360 nm and emits in the blue at 426 and 451 nm. The band-gap calculated from the UV-vis spectrum was about 2.80 eV. A single-layer device of the configuration indium tin oxide (ITO)/BPAEt2 -BP/Al has a relatively low turn-on voltage of 3 V. Copyright © 2005 Society of Chemical Industry [source] Charge-Transporting Polymers based on Phenylbenzoimidazole MoietiesADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Marc Debeaux Abstract A series of novel styrene functionalized monomers with phenylbenzo[d]imidazole units and the corresponding homopolymers are prepared. These side-chain polymers show high glass-transition temperatures that even exceed the corresponding value for the common electron-transporting material 1,3,5-tris(1-phenyl-1H -benzo[d]imidazol-2-yl)benzene (TPBI). Similar electronic behavior between the polymers and TPBI is shown. The polymers are used as matrices for phosphorescent dopants. The fabricated devices exhibit current efficiencies up to 38.5,cd A,1 at 100,cd,m,2 and maximum luminances of 7400,cd m,2 at 10,V with a minimum turn-on voltage as low as 2.70,V in single-layer devices with an ITO/PEDOT:PSS anode (ITO,=,indium tin oxide, PEDOT:PSS,=,poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate)) and a CsF/Ca/Ag cathode. [source] New synthesis of highly potential efficient bluish-green electroluminescent materials based on 1,3,4-oxadiazole,triazolopyridinone,carbazole derivatives for single-layer devicesHETEROATOM CHEMISTRY, Issue 2 2006Ming-Hsiang Shin New potential bluish-green electroluminescent materials of 1,3,4-oxadiazole,triazolopyridin- one,carbazole derivatives were synthesized and characterized for single-layer devices. Carbazole, pyridine, and triazolopyridinone were completely introduced into 1,3,4-oxadiazole skeletal to play assistant roles in controlling fundamental photolytic process due to the electron-donating nature, excellent photoconductivity, and flexible structure properties. Following the spectroscopic studies and the measurements of cyclic voltammogram, 1,3,4-oxadiazole,triazolopyridinone,carbazole derivatives were highly efficient bluish-green electroluminescent materials. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:160,165, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20201 [source] | |||||||||||||