Erratum: "Green fluorescent organic light-emitting device with external quantum efficiency of nearly 10%" [Appl.Improving organic light-emitting devices by modifying indium tin oxide anode with an ultrathin tetrahedral amorphous carbon film

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A new class of hole-blocking amorphous molecular materials for use in organic electroluminescent (EL) devices have been developed, which include 1,3,5-tri(4-biphenylyl)benzene, 1,3,5-tris(4-fluorobiphenyl-4′-yl)benzene (F-TBB), 1,3,5-tris(9,9-dimethylfluoren-2-yl)benzene, and 1,3,5-tris[4-(9,9-dimethylfluoren-2-yl)phenyl]benzene. They readily form stable amorphous glasses with well-defined glass-transition temperatures and are characterized by relatively high oxidation potentials and large HOMO-LUMO energy gaps. The use of these materials as hole blockers enabled blue-violet emission from several emitting amorphous molecular materials with hole-transporting properties in organic EL devices. A multilayer organic EL device using N,N-bis(9,9-dimethylfluoren-2-yl)aniline (F 2 PA) as a blue-violet emitter, F-TBB as a hole blocker, and 4,4′,4′′-tris[3-methylphenyl(phenyl)amino]triphenylamine and tris(8-quinolinolato)aluminum as hole and electron transporters, respectively, exhibited blue-violet emission peaking at 405 nm with a high external quantum efficiency of 1.95%. This device also enabled the doping of a phosphorescent iridium complex, tris(2phenylpyridine)iridium (Ir(ppy) 3 ), tuning the emission color from blue violet to green by excitation energy transfer from F 2 PA to Ir(ppy) 3 .

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Red organic light-emitting devices (OLEDs) have been developed employing a novel fluorescent emitting layer, tetraphenyldibenzoperiflanthene-doped rubrene. The devices are characterized by low driving voltage below 4V at a current density of 20mA∕cm2 and high color purity with Commission Internationale de l’Eclairage coordinates of (0.66, 0.34). The OLED using the novel emitting layer in combination with the electron-transporting layer consisting of 9,10-bis[4-(6-methylbenzothiazol-2-yl)phenyl]anthracene exhibits a high power efficiency of 5.3lm∕W at a current density of 20mA∕cm2. The half-luminance lifetime of the red OLED is 223h at a current density of 80mA∕cm2 (initial luminance of 3570cd∕m2). Both the driving voltage and current efficiency of the device are significantly improved compared to a device using tris(8-quinolinolato)aluminum as an electron-transporting layer. The studies on charge transport for the host materials indicate that the high efficiency is attributed to the improved charge injection and balance in the device.