Anja Gerhard

Deep blue widely tunable organic solid-state laser based on a spirobifluorene derivative

We report on amplified spontaneous emission and optically pumped deep blue lasing in the organic spirobifluorene derivative 2,7-bis(biphenyl-4-yl)-2′,7′-di-tert-butyl-9,9′-spirobifluorene. Solid-state lasing is observed in thin films of this material deposited on a distributed-feedback (DFB) grating substrate. The laser wavelength can be tuned from 401.5 to 434.2 nm depending on the grating period of the Bragg reflector. The blue edge of this interval at 401.5 nm makes this laser an extremely short wavelength organic DFB laser. When pumping with a pulsed nitrogen laser at 337 nm, we observe a laser threshold energy density of 83 μJ/cm2. These results render this spiro compound an excellent candidate for blue-emitting diode lasers.

22.2: Novel Triplet Host Materials: High Performance Made Easy

Novel materials are the key to high performance phosphorescent devices. New host materials show significant advantages over the currently used class of carbazole based materials. A significantly simpler device structure can be used applying the new material classes. Compared to the classical triplet device structure (employing electron transport layers and hole-blocking layers) an even better EL performance in terms of efficiency and lifetime is observed.

17.5L: Late-News Paper: Novel Host Materials for Efficient and Stable Phosphorescent OLED Devices

A new class of matrix materials for phosphorescent OLEDs has been developed. Those materials show significant advantages over the currently used class of carbazole based materials. Device lifetime could be prolonged by a factor of 6 while significantly improving power efficiencies.