The present invention includes novel platinum complexes with tridentate ligands forming dimeric structures that are calculated to have blue emission. The ligand backbone and pendant donor rings can be altered to give different emission maxima. The present invention also includes various pendant donor rings and multiple different ligand backbones. Such complexes are suitable for use as an emitter in organic light emitting devices.

To provide an organic electroluminescent device having high efficiency and high driving stability while having a low driving voltage. The organic electroluminescent device has one or more light-emitting layers between an anode and a cathode opposed to each other, wherein at least one of the light-emitting layers is a light-emitting layer composed of a vapor deposition layer containing a first host, a second host and a light-emitting dopant material; the first host is selected from oligopyridine compounds represented by the general formula (1); and the second host is selected from carbazole compounds having two or more carbazole rings, indolocarbazole compounds having an indolocarbazole ring or compounds having a carbazole ring and an indolocarbazole ring.

Provided are organometallic compounds that includes a ligand L.sub.A of

##STR00001##

Also provided are formulations comprising these organometallic compounds. Further provided are OLEDs and related consumer products that utilize these organometallic compounds.

A organic light-emitting element including a positive electrode, a light-emitting layer, and a negative electrode in this order, wherein the light-emitting layer contains a dopant material, a host material, and an assist material, the dopant material is a compound represented by the following general formula [1], the host material is a hydrocarbon compound, and the assist material has a lower LUMO level than the host material. In the formula [1], R.sub.1 to R.sub.10 denote a hydrogen atom, an alkyl group, or the like. X denotes O or S. m denotes an integer in the range of 1 to 3, and n denotes an integer in the range of 0 to 2, provided that m+n is 3. The partial structure IrL.sub.n is any one of structures represented by the following formulae [2] and [3], wherein R.sub.11 to R.sub.21 denote a hydrogen atom, an alkyl group, or the like.

##STR00001##

The present application relates to a technical filed of energy sources and illumination, and discloses a rare earth oxide nanosheet composite modified by an organic ligand, a preparation method and an organic light-emitting diode (OLED) luminescent film. The rare earth oxide nanosheet composite modified by the organic ligand is obtained by adding the organic ligand in the rare earth nanosheet sol for ultrasonic coordination; and a mole ratio of the rare earth nanosheet sol to the organic ligand is 1:(3-9).

Provided are organometallic compounds. Also provided are formulations comprising these organometallic compounds. Further provided are OLEDs and related consumer products that utilize these organometallic compounds.

An organic electroluminescence device of an embodiment includes a first electrode, a second electrode, and an emission layer between the first electrode and the second electrode, wherein the emission layer includes a polycyclic compound represented by Formula 1 and shows high emission efficiency and excellent color reproducibility. ##STR00001##

Provided are compounds having the structure of Formula I:

##STR00001##

Formula I;

wherein A is B, Al, Bi, or is not present; and L.sup.1-L.sup.4 are each independently selected from the group consisting of O, S, Se, NR, BR, BRR′, CRR′, SiRR′, GeRR′, P(O)R, and C═X; and L.sup.3 and L.sup.4 are each optionally present; wherein each R, R′, R″, R″″, R.sup.A, R.sup.B, R.sup.C, R.sup.D, R.sup.E, R.sup.F, and R.sup.G is hydrogen or a substituent; and any two adjacent R, R′, R″, R″″, R.sup.A, R.sup.B, R.sup.C, R.sup.D, R.sup.E, R.sup.F, and R.sup.G can be joined or fused to form a ring. Also provided are formulations comprising these compounds. Further provided are OLEDs and related consumer products that utilize these compounds.

A condensed cyclic compound represented by Formula 1:

##STR00001## wherein in Formula 1, Ar and R.sub.1 to R.sub.8 are the same as described in the specification.

A ligand for metal complexes are disclosed, in which an imidazole ring is fused to an aromatic ring as a substituent or an imidazole ring is fused to a six-member ring of the original ligand. The features of these elements within the ligand afford a better device performance in general OLED device.