Takanori Fujii

Organic Electroluminescent Devices with 8-Hydroxyquinoline Derivative-Metal Complexes as an Emitter

Organic electroluminescent (EL) devices with 8-hydroxy-quinoline derivative-metal complexes (Znq2, Beq2, Mgq2, ZnMq2, BeMq2 and AlPrq3) as the emitter have been developed. The emissions of these devices are green or yellow. These devices have a luminance of more than 3000 cd/m2. In particular, the EL device with Znq2 has a luminance of 16200 cd/m2.

Novel Europium Complex for Electroluminescent Devices with Sharp Red Emission.

A volatile Eu complex, Eu(TTA)3(phen) (TTA=thenoyltrifluoroacetone, phen=1,10-phenanthroline), was synthesized and applied to an electroluminescent (EL) cell structure of [ITO(=indium-tin-oxide)/hole transporting layer/emitting layer (host material=azomethin zinc complex, and dopant= Eu(TTA)3(phen))/MgIn]. The emitting layers were formed by a codeposition technique. A red emission (EL peak wavelength 614 nm) with a very sharp spectral band was observed from the EL cell with 5 wt% Eu(TTA)3(phen), and a maximum luminance of 137 cd/m2 was achieved.

Blue Electroluminescence in Thin Films of Azomethin-Zinc Complexes

Organic electroluminescent (EL) cells with azomethin-zinc complexes as an emitting layer showed bright blue emission. A cell structure of [indium-tin-oxide (ITO)/hole transport layer/emitting layer/MgIn] was employed. The color was blue, and emission peaks were 458?470 nm. High luminance exceeding 1000 cd/m2 was obtained for the first time with an EL cell using a complex emitting material. The azomethin-zinc complexes exhibited good electron transport, as indicated by the high luminance obtained in two-layer EL cells.

Pyrazoline Dimers for Hole Transport Materials in Organic Electroluminescent Devices

Dimer structures of pyrazoline derivatives were synthesized in order to obtain stable films and applied to electroluminescent (EL) devices as hole transport material. A device structure of [indium-tin-oxide (ITO)/hole transport layer (HTL)/emitting layer (EML)/MgIn] was employed. When pyrazoline dimer (PYR-D3) and tris(8-hydroxyquinolinate)aluminum ( Alq3) were used as HTL and EML, respectively, the EL device showed a maximum luminance of 12400 cd/m2 at 11 V and a maximum luminous efficiency of 1.5 lm/W at 250 cd/m2. This showed that pyrazoline dimers functioned well as hole transport layers.