An organic electroluminescence device of an embodiment includes a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region, wherein the emission layer includes a polycyclic compound represented by Formula 1, thereby exhibiting high emission efficiency. ##STR00001##

Provided are a condensed cyclic compound having a novel structure and an organic light-emitting device including the same. The organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; an organic layer located between the first electrode and the second electrode and including an emission layer; and at least one condensed cyclic compound represented by Formula 1. ##STR00001##

A compound of Formula 1 and an organic light emitting device including the same, the compound used as a material for an organic material layer of the organic light emitting device, and providing high efficiency and low voltage characteristics of the organic light emitting device. ##STR00001##

A compound is described as having a triplet excited state and a singlet excited state; wherein the triplet excited state comprises a lowest energy triplet sublevel, a middle energy triplet sublevel, and a highest energy triplet sublevel; and wherein an energy separation between the highest energy triplet sublevel and the lowest energy triplet sublevel (ZFS) is greater than an energy separation between the singlet excited state and a the lowest energy triplet sublevel. Also described is a compound represented by the following Formula I. These compounds should find application as luminescent materials in organic light emitting diodes (OLEDs). ##STR00001##

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode and including an emission layer, wherein the interlayer includes a hole injection layer and a hole transport layer between the first electrode and the emission layer, the hole injection layer directly contacts the first electrode, the hole injection layer has a multi-layered structure of at least two different layers that are stacked on each other, the hole injection layer includes at least one inorganic material of a post-transition metal, a metalloid, a compound including at least two post-transition metal elements, a compound including at least two metalloid elements, or a compound including a post-transition metal element and a metalloid element, the post-transition metal and the metalloid are described herein.

An organic electroluminescence device includes an anode, a cathode, and an emitting layer provided between the anode and the cathode. The emitting layer contains a compound M3 represented by a formula (1-1) or (1-2) and a delayed fluorescent compound M2. The compound M3 and the compound M2 are mutually different in structure. A singlet energy S.sub.1(M3) of the compound M3 and a singlet energy S.sub.1(M2) of the compound M2 satisfy a relationship of S.sub.1(M3)>S.sub.1(M2). In the formulae (1-1) and (1-2), A is a group represented by a formula (11A) or the like, L.sub.1 and L.sub.2 are each independently a single bond or a substituted or unsubstituted arylene group, and Y.sub.1 is an oxygen atom or a sulfur atom.

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Embodiments provide a condensed cyclic compound, a light-emitting device including the condensed cyclic compound, and an electronic apparatus including the light-emitting device. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode, wherein the interlayer includes an emission layer, and the condensed cyclic compound. The condensed cyclic compound is represented by Formula 1, which is explained in the specification:

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A light-emitting element having high emission efficiency is provided.

The light-emitting element includes a first organic compound, a second organic compound, and a third organic compound. The first organic compound has a function of converting triplet excitation energy into light emission. The second organic compound is preferably a TADF material. The third organic compound is a fluorescent compound. Light emitted from the light-emitting element is obtained from the third organic compound. Triplet excitation energy in a light-emitting layer is transferred to the third organic compound by reverse intersystem crossing caused by the second organic compound or through the first organic compound.

A display device includes a first pixel, a second pixel, and a third pixel respectively including first, second, and third light-emitting elements configured to emit red light, green light, and blue light, respectively. Each of the first light-emitting element, the second light-emitting element, and the third light-emitting element includes a pixel electrode, an electron-blocking layer over the pixel electrode, an emission layer over the electron-blocking layer, a hole-blocking layer over the emission layer, and a counter electrode over the hole-blocking layer. The third light-emitting element further includes a first buffer layer between the emission layer and the hole-blocking layer. The emission layers of the first light-emitting element and the second light-emitting element include a thermally activated delayed-fluorescence material. The emission layer of the third light-emitting element includes a first fluorescence material having a fluorescence lifetime equal to or longer than 1 ps and shorter than 1 ns.

The present invention discloses novel Pt(IV) compounds useful for enhancing the performance of organic electroluminescent devices.