A compound comprising a ligand of L.sub.A of Formula I,

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is provided with variables as defined herein. Formulations, OLEDs, and consumer products including the compound are also disclosed.

A light-emitting device having favorable heat resistance is provided. The light-emitting device includes an anode, a cathode, and an EL layer positioned between the first anode and the cathode. The EL layer includes a light-emitting layer and a first layer. The first layer is positioned between the light-emitting layer and the cathode. The light-emitting layer and the first layer are in contact with each other. The light-emitting layer contains a first organic compound, a second organic compound, and a light-emitting substance. The first layer contains a third organic compound. The first organic compound and the third organic compound each have an electron-transport property. The second organic compound has a hole-transport property. The light-emitting substance emits red light. The first organic compound is represented by General Formula (G100). The third organic compound is represented by General Formula (G300).

##STR00001##

The present specification provides a heterocyclic compound represented by Chemical Formula 1, an organic light emitting device including the same, and a composition for an organic material layer of the organic light emitting device.

Tetradentate and octahedral metal complexes suitable for use as phosphorescent or delayed fluorescent and phosphorescent emitters in display and lighting applications.

An organic electroluminescence device includes a first electrode, a second electrode, and an emission layer disposed between the first electrode and the second electrode, wherein the emission layer includes a fused polycyclic compound represented by Formula 1, and thus the organic electroluminescence device may exhibit increased luminous efficiency.

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Disclosed is an organic light emitting device including a first electrode, a second electrode opposite to the first electrode, and at least one organic layer interposed between the first and second electrodes. The organic layer includes first and second compounds represented by Formulae A and B, respectively: ##STR00001## The organic light emitting device exhibits low driving voltage, high efficiency, and long life. Due to these advantages, the organic light emitting device is useful in a variety of industrial applications, including displays and lighting systems.

The present disclosure relates to an organic electroluminescent compound, an organic electroluminescent material and an organic electroluminescent device comprising the same, a plurality of host materials comprising at least one first host material and at least one second host material, and an organic electroluminescent device comprising the same. By comprising the compound according to the present disclosure as a single host material or as a plurality of host materials, it is possible to produce an organic electroluminescent device having improved driving voltage, luminous efficiency, and/or lifetime properties compared to the conventional organic electroluminescent devices.

A compound having the structure of Formula I,

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is provided. In Formula I, M is Pt or Pd; moieties A, B, C, and D are each monocyclic or multicyclic ring system; K.sup.1, K.sup.2, K.sup.3, and K.sup.4 are selected from a direct bond, O, S, and Se; when present, each of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 is a direct bond or a linker; at least three of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 are present; and the compound comprises at least one structure

##STR00002##

Formulations, OLEDs and consumer products containing the compound are also provided.

The present invention provides a compound, an organic electroluminescence material, an organic electroluminescence element and an electronic device. When the compound is used as the material of the organic functional layers, it makes the element have a lower driving voltage, a higher current efficiency and a longer service life.

A compound for an organic optoelectronic device, an organic optoelectronic device including the same, and a display device, the compound being represented by Chemical Formula I:

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