TY  - JOUR
A1  - Yang, X. H.
A1  - Neher, Dieter
T1  - Polymer electrophosphorescence devices with high power conversion efficiencies
N2  - We demonstrate efficient single-layer polymer phosphorescent light-emitting devices based on a green-emitting iridium complex and a polymer host co-doped with electron-transporting and hole-transporting molecules. These devices can be operated at relatively low voltages, resulting in a power conversion efficiency of up to 24 lm/W at luminous efficiencies exceeding 30 cd/A. The overall performances of these devices suggest that efficient electrophosphorescent devices with acceptable operating voltages can be achieved in very simple device structures fabricated by spin coating. (C) 2004 American Institute of Physics
Y1  - 2004
SN  - 0003-6951
ER  - 
TY  - JOUR
A1  - Yang, X. H.
A1  - Neher, Dieter
A1  - Hertel, D.
A1  - Daubler, T. K.
T1  - Highly efficient single-layer polymer electrophosphorescent devices
N2  - A commercially available Ir complex has been employed for the preparation of highly efficient (see Figure) single-layer phosphorescent polymer light,emitting diodes by use of appropriate thermal treatment and proper adjustment of the layer composition. These devices exhibit essentially no dependence of the driving field on the concentration of the Ir complex, suggesting that the build-up of space-charge in the layer is insignificant
Y1  - 2004
SN  - 0935-9648
ER  - 
TY  - JOUR
A1  - Qu, J. Q.
A1  - Zhang, J. Y.
A1  - Grimsdale, A. C.
A1  - Mullen, K.
A1  - Jaiser, Frank
A1  - Yang, X. H.
A1  - Neher, Dieter
T1  - Dendronized perylene diimide emitters : Synthesis, luminescence, and electron and energy transfer studies
N2  - Aggregation of chromophores in the solid state commonly causes undesirable red shifts in the emission spectra and/or emission quenching. To overcome this problem, we have prepared soluble perylenetetracarboxidiimide dyes in which the chromophores are effectively shielded by polyphenylene dendrimers attached in the bay positions. Models show that attachment of the shielding units in the bay position should provide more efficient shielding than attaching them via the imide moieties. The dendrimers possess excellent film-forming properties due to alkyl substituents on their peripheries. The lack of a red shift in emission upon going from solution to the solid state indicates the dendrons suppress interaction of the emissive cores, leading to pure red-orange emission. Single-layer LEDs produce red-orange emission with relatively low efficiency especially for the higher generation dendrons, which is attributed to poor charge conduction. LEDs using blends of the dendrimers and the undendronized dye as a model compound in PVK have been investigated, and a model to extract relative charge injection rates through the dendritic scaffold from the spectral contributions in the EL spectra is developed
Y1  - 2004
SN  - 0024-9297
ER  - 
TY  - JOUR
A1  - Galbrecht, Frank
A1  - Yang, X. H.
A1  - Nehls, B. S.
A1  - Neher, Dieter
A1  - Farrell, Tony
A1  - Scherf, Ullrich
T1  - Semiconducting polyfluorenes with electrophosphorescent on-chain platinum-salen chromophores
N2  - The synthesis of statistical fluorene-type copolymers with on-chain Pt-salen phosphorescent units and their use in electrophosphorescent OLEDs is reported
Y1  - 2005
SN  - 1359-7345
ER  - 
TY  - JOUR
A1  - Yang, X. H.
A1  - Jaiser, Frank
A1  - Klinger, S
A1  - Neher, Dieter
T1  - Blue polymer electrophosphorescent devices with different electron-transporting oxadiazoles
N2  - We report that the performances of blue polymer electrophosphorescent devices are crucially depending on the choice of the electron transporting material incorporated into the emissive layer. Devices with 1,3-bis[(4-tert- butylphenyl)-1,3,4-oxidiazolyl]phenylene (OXD-7) doped at similar to 40 wt% into a poly(vinylcarbazole) matrix exhibited significantly higher efficiencies than those with 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), yielding maximum luminous and power efficiency values of 18.2 Cd/A and 8.8 lm/W, respectively. Time resolved photoluminescence measurements revealed a long lifetime phosphorescence component in layers with PBD, which we assign to significant triplet harvesting by this electron-transporting component. (c) 2006 American Institute of Physics
Y1  - 2006
UR  - http://scitation.aip.org/getpdf/servlet/ GetPDFServlet?filetype=pdf&id=APPLAB000088000002021107000001&idtype=cvips&doi=10.1063/1.2162693&prog=normal
U6  - https://doi.org/10.1063/1.2162693
ER  -