To provide a light-emitting element which uses a fluorescent material as a light-emitting substance and has higher luminous efficiency. To provide a light-emitting element which includes a mixture of a thermally activated delayed fluorescent substance and a fluorescent material. By making the emission spectrum of the thermally activated delayed fluorescent substance overlap with an absorption band on the longest wavelength side in absorption by the fluorescent material in an S.sub.1 level of the fluorescent material, energy at an S.sub.1 level of the thermally activated delayed fluorescent substance can be transferred to the S.sub.1 of the fluorescent material. Alternatively, it is also possible that the S.sub.1 of the thermally activated delayed fluorescent substance is generated from part of the energy of a T.sub.1 level of the thermally activated delayed fluorescent substance, and is transferred to the S.sub.1 of the fluorescent material.

A compound for an organic optoelectronic device represented by Chemical Formula 1 ##STR00001##
wherein groups R.sub.1-R.sub.4, Ar.sub.1, Ar.sub.2, L.sub.1, L.sub.2, X, n.sub.1, and n.sub.2 are described in the specification.

The present specification relates to an organic light emitting device including: a cathode; an anode; a light emitting layer provided between the cathode and the anode; and one or more organic material layers provided between the cathode and the light emitting layer.

Provided is an organic light-emitting device including a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer. The emission layer includes a first compound represented by Formula 1-1 or Formula 1-2 below, a second compound represented by Formula 2 below, and a third compound represented by Formula 3 below: ##STR00001##
where Ar1 to Ar8, R1 to R3, A, L1, L2, a1, a2, b1, b2, c1, c2, l1, and l2 are as defined in the specification.

The present invention relates to metal complexes and to electronic devices, especially organic electroluminescent devices, comprising these metal complexes, especially as emitters.

A heterocyclic compound represented by Formula 1 below and an organic light-emitting device including the heterocyclic compound are provided: ##STR00001##

An organic light-emitting device includes a first electrode, a second electrode facing the first electrode, and an emission layer disposed between the first electrode and the second electrode. An electron transport region is between the second electrode and the emission layer. The electron transport region includes an electron injection layer including a first component including at least one halide of an alkali metal (Group I), a second component including at least one organometallic compound, and a third component including at least one of a lanthanide metal or an alkaline earth metal (Group II).

The present invention relates to an emissive film comprising a network of crosslinked nanocrystals, wherein said network of crosslinked nanocrystals is formed from reactive colloidal nanocrystals comprising a core comprising a semiconductive compound and at least one polythiol ligand, and wherein said core is surrounded by at least one polythiol ligand, and wherein each core surrounded by at least one polythiol ligand is crosslinked with at least one another polythiol ligand surrounding another core. The photoluminescent properties of the NCs are preserved once the film is formed. A light emitting device (LED) is fabricated using an emissive film as the emissive layer. The LED emits light when an electrical current flows through the device, which proves the electroluminescent properties of the NCs film.

An organic electroluminescent element having a small reduction rate in the luminance immediately after the start of light emission is provided. The organic electroluminescent element includes a substrate, a pair of electrodes including an anode and a cathode, disposed on the substrate, a light emitting layer disposed between the electrodes, and at least one organic layer disposed between the light emitting layer and the anode, in which at least one kind of a specific compound including a fluorene structure is contained in at least one organic layer between the light emitting layer and the anode, and at least one kind of a specific compound including a carbazole structure or a fluorene structure is contained as a light emitting material in the light emitting layer.

To provide a light-emitting element which uses a fluorescent material as a light-emitting substance and has higher luminous efficiency. To provide a light-emitting element which includes a mixture of a thermally activated delayed fluorescent substance and a fluorescent material. By making the emission spectrum of the thermally activated delayed fluorescent substance overlap with an absorption band on the longest wavelength side in absorption by the fluorescent material in an S.sub.1 level of the fluorescent material, energy at an S.sub.1 level of the thermally activated delayed fluorescent substance can be transferred to the S.sub.1 of the fluorescent material. Alternatively, it is also possible that the S.sub.1 of the thermally activated delayed fluorescent substance is generated from part of the energy of a T.sub.1 level of the thermally activated delayed fluorescent substance, and is transferred to the S.sub.1 of the fluorescent material.