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By combining supercritical drying technique with AAO template-assisted electrodeposition, noncollapsed, vertically aligned, and free-standing nanowire arrays on a conductive Au film have been fabricated. We also demonstrate that these free-standing nanowire arrays can be feasibly used for fabricating nanowire-based electrically driven devices.

[structure: see text] Novel solution-processable blue light-emitting materials Blue A-D, bearing a polyphenylphenyl dendron, have been synthesized and characterized. The energy levels and band gaps can be facilely tuned by changing the central aromatic ring of the molecules. A highly efficient deep blue light-emitting OLED device based on Blue C with a maximum current efficiency of 2.2 cd/A has been achieved using PVK as the host material through a solution process.

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A novel solution processable phosphorescent dendrimer based on cyclic phosphazene (CP) cores has been prepared and used as emissive layers in simple OLED architectures, providing efficiencies of 24.0 cd A 21 and 16.7 lm W 21 .Organic and polymeric light emitting diode (OLED) technology has progressed immensely since the initial reports by Tang 1 and Friend 2 in 1987 and 1990 respectively. From these earliest discoveries through the late 1990's, almost all OLED reports were based on fluorescent emissive materials. As a result, champion OLED efficiencies were limited to around 10 lm W 21 which made their application in display technology promising but no chance for solid-state lighting that requires efficiencies of .30 lm W 21 . With the discovery of platinum and iridium based phosphorescent complexes, 3,4 OLED efficiencies .30 lm W 21 have been achieved and thus application in both display and lighting applications have become even more promising. 5 For these active materials, both small molecules and polymers are currently the preferred candidates. Small-molecules are advantageous as they can be highly purified and vacuum deposited in multi-layer stacks, both important for device lifetime and efficiency. However, vacuum deposition techniques generally require expensive equipment, a limitation to display size, and complicated full color display production processes at high volume using masking technologies. 6 Polymers are generally of lower purity than small molecules but can access larger display sizes at much lower costs using solution-based deposition techniques such as spray coating, ink jet and screen printing. 7,8 Having a set of materials with properties intermediate between small molecules and polymers would be very advantageous. One such family of materials are dendrimers that have molecular weights in the favorable range between 1000-10 000 g mol 21 . Favorable because dendrimers can be purified to a high degree using chromatographic techniques, are soluble in common solvents, and allow synthetic versatility for tuning charge transport 9-12 and emissive [13][14][15][16] properties. Finally dendrimers of different emission colors can be physically blended together without phase separation for possible application in white lighting.Cyclic phosphazenes (CP), with a planar non-delocalized cyclic ring consisting of alternating N and P atoms, are an interesting class of materials that offers access to dendrimeric materials. The inorganic phosphazenes have been well studied in both the cyclic and linear forms by several groups due to their diverse properties including excellent hydrolytic stability, thermal stability, flame retardant properties, and liquid crystalline behaviour to name a few. [17][18][19][20] The CP core provides many advantageous properties towards useful materials for solution processable OLEDs. First, the chemistry to prepare functionalized CP cores is very straightforward. Second, the functionalized CP cores are very stable and do not breakdown even under very aggressive chemical condition...

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The incorporation of electroluminescence and electrochemiluminescence in one light-emitting device with the configuration of indium tin oxide (ITO)/[Ru(bpy)2(dimbpy)](PF6)2∕Alq3(30nm)∕NPB(45nm)∕Ag(60nm) is investigated. When the ITO and Ag electrodes are negatively and positively biased respectively, the color of the emission changes from green to light yellow-white within 100 s. So there is only one recombination zone in the bulk of the Alq3 at the initial stage of the operation, followed by the formation of another recombination zone in the bulk of the [Ru(bpy)2(dimbpy)](PF6)2. This directly indicates the existence of unipolar injection (electron injection) process in the ruthenium complex layer. The external quantum efficiency of the device is 1.4% compared with 0.45% of the ITO∕[Ru(bpy)2(dimbpy)](PF6)2∕Ag device, improved by twofold. Furthermore, this hybrid device provides a feasible way to control the emission of a wide spectrum of colors including red, green, yellow, and white.