Rare‐earth chelate phosphors for organic EL devices

The electroluminescence (EL) of the Tb complex [Tb(ACA) 3 phen] and the Eu complex [Eu(TTA) 3 (TPPO) 2 ] used for organic LEDs was investigated, and a luminance of 210 cd/m 2 with sharp green bands for the organic LEDs containing Tb(II was achieved. It was found that the EL properties of the devices using the Tb complex as the emitter depend on the hole-transporting layers. We have also noticed that the Tb complex plays an electron-transporting-layer role when the device has the ITO/Eu complex/Tb complex/Al structure.