High-performance organic red-light-emitting devices based on a greenish-yellow-light-emitting host and long-wavelength emitting dopant

We demonstrated an organic red-light-emitting device (ORLED) using a host, 5,6-bis-[4-(naphthalene-1-yl-phenyl-amino)-phenyl]-pyrazine-2,3-dicarbonitrile (BNPPDC), and a dopant, 2,3-bis[[[(2-hydroxy-4-diethylamino)phenyl] (methylene)] amino]-2-butanedinitrile (BDPMB). The device achieved a brightness of 9730 cd m2 at a 11 V, a power efficiency of 2.35 lmW, a current efficiency of 3.36 cdA at 4.5 V, and a low turn-on voltage of 3.0 V, with nearly saturated red emission. The device is superior or equal to the best fluorescent ORLEDs reported. BNPPDC generally induced a significant blueshift in dopant emission, thus it may serve as a host for dopants emitting at long wavelengths in ORLEDs with improved performance. © 2006 American Institute of Physics.