An organic light-emitting device including a first compound represented by Formula 1 and a second compound represented by one of Formulae 2A and 2B. ##STR00001##

Disclosed is a novel organometallic compound in which a main ligand (L.sub.A) has a fused ring structure including a thiophene group. The organometallic compound acts as a dopant of a phosphorescent light-emitting layer of an organic light-emitting diode. Thus, an operation voltage of the diode is lowered, and luminous efficiency and a lifespan thereof are improved.

Luminescent solar concentrator (LSC) comprising an aqueous microemulsion including at least one photoluminescent compound. Said luminescent solar concentrator (LSC) can be advantageously used in solar devices (i.e. devices for exploiting solar energy) such as, for example, photovoltaic cells (or solar cells), photoelectrolytic cells. Said luminescent solar concentrator (LSC) can also be advantageously used in photovoltaic windows.

Provided is a thiadiazole compound with high efficiency and long life which emits light in a near-infrared region and represented by Formula (I).

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In the Formula (I), As each independently represent an aryl group which may have a substituent or a diarylamino group.

Disclosed in the present invention is a deuterated indolocarbazole compound, mixture and formulation comprising the said compound, and an organic electronic device. For said deuterated indolocarbazole compound, in an indolocarbazole conjugated system, a C—H bonding is optionally replaced by a C-D bonding, thus reduces the reactivity of the compound and moreover allowing the superior chemical and environmental stability. The present invention applies the deuterated indolocarbazole compound to the organic electronic device and provided is a solution for improving the stability and lifespan of the device.

A novel organometallic compound represented by a following Chemical Formula I is described:

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wherein R represents a fused ring connected to X.sub.1 and X.sub.2, with variables as defined herein. The organometallic compound acts as a dopant of a light-emitting layer of an organic light-emitting diode. An organic light emitting device includes the organic light emitting diode and can be a display device or a lighting device. Improved color gamut of the diode, luminous efficiency and a lifespan thereof are achieved, as well as a lower operation voltage of the diode.

The present invention relates to a novel indole-based compound having excellent hole injection and transport capabilities, light-emitting capabilities, and the like, and an organic electroluminescence device which includes the indole-based compound in one or more organic material layers thereof so as to improve characteristics such as light-emitting efficiency, driving voltage, and lifespan.

Embodiments relate to a delayed fluorescence compound and a display device including the delayed fluorescence compound. The delayed fluorescence compound includes an electron acceptor moiety of benzo[4,5]thieno[2,3-b]quinoxaline and at least one electron donor moiety covalently bonded to the electron acceptor moiety. The at least one electron donor moiety is covalently bonded to a benzene ring of benzo[4,5]thieno[2,3-b]quinoxaline and is selected from carbazole, phenylcarbazole, acridine, and phenylacridine. The effective charge transfer in the delayed fluorescence compound results in improved emitting efficiency of the compound.

An organic light-emitting element which emits delayed fluorescence comprising specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives or 1,2,4-thiadiazole derivatives in the light-emitting layer, a light-emitting layer comprising the specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives or 1,2,4-thiadiazole derivatives, specific specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives and 1,2,4-thiadiazole derivatives and an organic light emitting element comprising the specific 1,2,4-azole derivatives as well as a light emitting layer comprising the specific 1,2,4-azole derivatives; the use of the specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives and 1,2,4-thiadiazole derivatives for electrophotographic photoreceptors, photoelectric converters, sensors, dye lasers, solar cell devices and organic light emitting elements, and the use of the specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives and 1,2,4-thiadiazole derivatives for generating delayed fluorescence emission.

Tetradentate ligands with rigid backbone for use as phosphorescent emitters, and devices, such as organic light emitting diodes are disclosed.