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Blue light-emitting anthracene derivatives end-capped with triphenylamine for efficient hole transportation have been designed and synthesized using two-step Suzuki coupling reactions. The compounds possess high glass transition temperatures for good thermal stability and strong blue emission in solution. Typical three-layer organic light-emitting devices (OLEDs) made from these compounds show highly efficient blue emission, which are better than or comparable to state-of-the-art fluorescent OLEDs performance. For example, 9-pyrenyl-10-(4-triphenylamine) anthrancene (PAA)-based nondoped device exhibits efficient blue emission with a maximum efficiency up to 7.9 cd/A (or 6.8 lm/W). Based on the good hole transport of the anthracene-triphenylamine derivatives, deep blue emitting devices with high efficiency were achieved by using the derivatives as both emitter and hole transporter.

A new bipolar molecule containing hole-transporting and electron-transporting moieties has been synthesized and characterized. The compound, 4,4′,4′′-tris(8-quinoline)-triphenylamine (TQTPA) exhibited good thermal stability and luminescence properties. A single-layer TQTPA light-emitting device shows sky blue emission with a low turn-on voltage of 2.8 V, a maximum brightness greater than 7500 cd/m 2 at 10 V, and a maximum current efficiency of 1.6 cd/A. Bipolar transport properties of TQTPA were investigated via the hole-only and electron-only devices. Using the bipolar molecule as a hole-transporter, a typical bilayer device with a configuration of ITO/TQTPA (60 nm)/Alq 3 (50 nm)/LiF (0.5 nm)/MgAg yields a maximum current efficiency of 5.6 cd/A (with Alq 3 emission), which is much better (50% higher) than that of the prototypical NPB-based device (3.8 cd/A) with a similar device structure.

Our structure consists of a photonic crystal slab patterned with a square array of air holes introduced into the dielectric slab and a mirror underneath, as illustrated in Figure 1. We choose the periodicity of the structure such that within the wavelength It is shown that a simple photonic crystal slab structure provides a powerful mechanism for the control of the polarization properties of light. For a lossless system, for a given incident light with any fixed polarization, one can generate arbitrary polarization in the reflected light, as one varies the direction of the incident light. In the lossy system, the capability for arbitrary polarization generation is still preserved for s-or p-polarized incident light. This capability for arbitrary polarization generation closely relates to the nontrivial topological properties of the reflection matrix of the structure and exists over a wide range of frequencies.

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A new blue emitter, 9,9-bis-(3-(9-phenyl-carbazoyl))-2,7-dipyrenylfluorene (DCDPF), has been synthesized and characterized. Organic light-emitting devices (OLEDs) using DCDPF as a nondoped emitter exhibits deep-blue emission with a peak at 458 nm and CIE coordinates of (0.15, 0.15). The maximum efficiency of the device is 4.4 cd/A (3.1 lm/W). The results suggest that the introduction of carbazole units at the 9-position of fluorene provides an effective way to suppress molecular aggregation which would cause red shift in emission.

Azobenzene-based polymeric nanoparticles have emerged as promising candidate for biological detection and controlled drug release in an anaerobic environment for colon disease treatment. Herein, we report a novel and efficient...