An organic compound and an organic light emitting device including the same are disclosed. For example, an organic compound is represented by the following chemical formula in which one of X and Y is N, and the other one of X and Y is O or S. The organic light emitting diode and the organic light emitting device each includes the organic compound.

##STR00001##

A light emitting device including a first electrode and a second electrode facing each other, and a first blue stack, a first charge generation layer, and a phosphorescent stack disposed between the first electrode and the second electrode. The phosphorescent stack includes a hole transport layer, a red light emitting layer, a green light emitting layer, and an electron transport layer. The red light emitting layer includes an electron transport host represented by Formula 1, a hole transport host different from the hole transport layer, and a red dopant.

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A light emitting element that includes a first compound represented by a specific chemical formula in which an ortho-type or kind penta-phenyl group is bonded to a fused polycyclic compound including at least one boron atom and a heteroatom is provided. The light emitting element has a long-lifetime.

An organometallic compound represented by Formula 1:

##STR00001##

wherein M.sub.1 is a transition metal, Ln.sub.1 is a ligand represented by Formula 1A, Ln.sub.2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2:

##STR00002##

##STR00003##

wherein ring CY.sub.3 is: a 5-membered N-containing heterocyclic group; or a 5-membered N-containing heterocyclic group condensed with a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, ring CY.sub.4 is: a 6-membered carbocyclic group; a 6-membered heterocyclic group; a 6-membered carbocyclic group condensed with a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group; or a 6-membered heterocyclic group condensed with a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, Y.sub.1 is O, S, Se, or C(R.sub.1)(R.sub.2), Y.sub.2 is O or S, and b30, b40, R.sub.1, R.sub.2, R.sub.11 to R.sub.14, R.sub.21 to R.sub.26, R.sub.30, and R.sub.40 are as defined herein.

Disclosed is a light emitting device that is capable of reducing lateral leakage current and a driving voltage by improving a structure for connecting a plurality of stacks to one another in a structure using the plurality of stacks, and a light emitting display device including the same. The light emitting device includes a first electrode and a second electrode facing each other, a plurality of stacks provided between the first electrode and the second electrode, and a charge generation layer including an electron generation layer and a hole generation layer stacked between the stacks, wherein the electron generation layer contains a first host of Formula 1 and a metal dopant, and the hole generation layer contains a second host and an organic dopant.

A light emitting element includes a first electrode, a second electrode, and an emission layer between the first electrode and the second electrode and includes a compound represented by Formula 1 below, thereby exhibiting a long service life characteristic.

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A display device includes a sacrificial layer positioned between an encapsulation layer and a light-emitting element that includes a first compound that is the same as a first compound of a light-emitting layer of the light-emitting element, thereby protecting the light-emitting element from an outgas of the encapsulation layer to prevent the generation of dark spots.

Provided are a heterocyclic compound represented by Formula 1, a light-emitting device including the heterocyclic compound, and an electronic apparatus including the light-emitting device:

##STR00001##

wherein the detailed description of Formula 1 is the same as described in the specification.

The present disclosure relates to a plurality of host materials comprising at least one first host compound represented by the following formula 1 and at least one second host compound represented by the following formula 2, and an organic electroluminescent device comprising the same. By comprising the specific combination of the compound according to the present disclosure as host materials, an organic electroluminescent device having high luminous efficiency and/or long lifespan characteristics can be provided.

Provided is an organic electroluminescent device. The organic electroluminescent device is a blue delayed fluorescent device including an anode, a cathode, an emissive layer disposed between the anode and the cathode and a hole blocking layer disposed between the emissive layer and the cathode, where the hole blocking layer comprises a hole blocking material having a structure of Formula 1, and the emissive layer comprises a first host material, a second host material and a blue delayed fluorescent material having a structure of Formula 3. The blue delayed fluorescent device exhibits excellent overall device performance, such as higher efficiency and longer lifetime. Further provided are a light-emitting device comprising a blue delayed fluorescent unit, a green phosphorescent unit and a red phosphorescent unit and a display assembly comprising the blue delayed fluorescent device and the light-emitting device.