Provided is a thermally activated delayed fluorescent organic electroluminescent device having a low driving voltage, high luminous efficiency, and a long lifetime. The organic electroluminescent device includes light-emitting layers between an anode and a cathode opposite to each other, and at least one of the light-emitting layers contains a thermally activated delayed fluorescent material, or the thermally activated delayed fluorescent material and a host material. The thermally activated delayed fluorescent material is represented by the following general formula (1) where A represents an electron-withdrawing group, such as a CN group, and D.sup.1 and D.sup.2 each represent an electron-donating group having an indole ring structure.

The present invention relates in part to compounds containing indolocarbazole and terphenyl building blocks. These compounds are useful for application in organic electroluminescent devices wherein the combination of indolocarbazoles with terphenyl groups leads to novel compounds that demonstrate superior device performance.

The present disclosure relates to an organic electroluminescent compound, an organic electroluminescent material comprising the same, and an organic electroluminescent device. By comprising the organic electroluminescent compound according to the present disclosure, an organic electroluminescent device having improved driving voltage and/or luminous efficiency and/or lifespan characteristics can be provided, compared with the organic electroluminescent device comprising a conventional organic electroluminescent compound.

A light-emitting element which uses a plurality of kinds of light-emitting dopants emitting light in a balanced manner and has high emission efficiency is provided. Further, a light-emitting device, a display device, an electronic device, and a lighting device each having reduced power consumption by using the above light-emitting element are provided. A light-emitting element which includes a plurality of light-emitting layers including different phosphorescent materials is provided. In the light-emitting element, the light-emitting layer which includes a light-emitting material emitting light with a long wavelength includes two kinds of carrier-transport compounds having properties of transporting carriers with different polarities. Further, in the light-emitting element, the triplet excitation energy of a host material included in the light-emitting layer emitting light with a short wavelength is higher than the triplet excitation energy of at least one of the carrier-transport compounds.

The present disclosure relates to an organic compound having the following structure, and an organic light emitting diode (OLED) and an organic light emitting device including the organic compound. The organic compound is a bipolar compound having a p-type moiety and an n-type moiety and has high energy level and proper energy bandgap for an emissive layer of the OLED. As the organic compound is applied into the emissive layer, the OLED can maximize its luminous properties as holes and electrons are recombined uniformly over the whole area in an EML. ##STR00001##

A light-emitting element which includes a plurality of light-emitting layers between a pair of electrodes and has low driving voltage and high emission efficiency is provided. A light-emitting element including first to third light-emitting layers between a cathode and an anode is provided. The first light-emitting layer includes a first phosphorescent material and a first electron-transport material; the second light-emitting layer includes a second phosphorescent material and a second electron-transport material; the third light-emitting layer includes a fluorescent material and a third electron-transport material; the first to third light-emitting elements are provided in contact with an electron-transport layer positioned on a cathode side; and a triplet excitation energy level of a material included in the electron-transport layer is lower than triplet excitation energy levels of the first electron-transport material and the second electron-transport material.

An organic light emitting diode comprises an emitting material layer implementing a delayed fluorescence and another emitting material layer disposed adjacently to the emitting material layer and implementing fluorescence or phosphorescence and an organic light emitting device including the diode. As exciton generated in the plural emitting material layer drops to a ground state through the luminous materials each of which has a controlled energy level, it is possible to implement excellent luminous efficiency derived from a delayed fluorescent material and improved color purity derived from a fluorescent or phosphorescent material having narrow FWHM.

Provided are compounds of Formula I ##STR00001##
that are useful as emitters in OLEDs.

A light-emitting device with high emission efficiency and reliability is provided. The light-emitting device includes a fluorescent light-emitting layer and a phosphorescent light-emitting layer. A host material used in the fluorescent light-emitting layer has a function of converting triplet excitation energy into light emission and a guest material used in the fluorescent light-emitting layer emits fluorescence. The guest material has a molecular structure including a luminophore and a protecting group, and one molecule of the guest material includes five or more protecting groups. The introduction of the protecting groups into the molecule inhibits transfer of triplet excitation energy from the host material to the guest material by the Dexter mechanism. An alkyl group or a branched-chain alkyl group is used as the protecting group. The longest wavelength absorption band in the absorption spectrum of the guest material in the phosphorescent light-emitting layer has an overlap with the emission spectrum of the host material in the phosphorescent light-emitting layer.

Provided are a compound capable of improving the light-emitting efficiency, stability, and lifespan of an element; an organic electronic element using same; and an electronic device thereof.