The metal-organic complexes of Sc, Y, La and lanthanides, which were tested as luminescent materials in organic light emitting diodes (OLEDs), are collected. The performances of the devices are given. Advantages and drawbacks of organic derivatives of rare earth metals as emissive materials are considered.

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Efficient electroluminescence (EL) was obtained in organic light-emitting devices using 8-quinolinolate complexes of scandium (Scq3) and yttrium (Yq3) as emitters. Compared to the device based on the analogous Alq3 complex, no notable difference in the EL performances of the Yq3 device can be found; however, the EL characteristics of device with Scq3 were significantly enhanced. The device with the configuration of indium tin oxide/ N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine/Scq3/Yb exhibits a maximum current efficiency of 4.6 cd/A and a maximum power efficiency of 2.6 lm/W at a luminance of 300 cd/m2. The improvement of the performance of this device should be attributed to the higher hole mobility of the Scq3 as compared to Alq3 or a smaller barrier for hole injection into Scq3 compared to Alq3.

Three members of a new class of electroluminescent, neutral, and monomeric scandium N,O-chelate complexes, namely, Sc(III)-tris-2-(2-benzoimidazol-2-yl)phenolate (1), Sc(III)-tris-2-(2-benzoxyazol-2-yl)phenolate (2), and Sc(III)-tris-2-(2-benzothiazol-2-yl)phenolate (3), have been prepared and X-ray characterized. DFT calculations have been performed. In contrast to the most frequently applied dual or multiple dopants in multilayer white OLED devices, all our simpler devices with the configuration of indium tin oxide/N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine/neat scandium complex/Yb exhibit close to near-white emission with a blue hue (CIE(x,y) = 0.2147, 0.2379) in the case of 1, a cyan hue (0.2702, 0.3524) in the case of 2, and a yellowish hue (0.3468; 0.4284) in the case of 3.