Provided are an organic compound and use thereof. The organic compound has a structure shown in Formula I. Through molecular structure design, the organic compound is endowed with suitable HOMO and LUMO energy levels, which is conducive to matching energy levels of compounds in adjacent layers and achieving efficient exciton recombination. The organic compound has small overlap of HOMO/LUMO energy level, high singlet energy level E.sub.S, high triplet energy level E.sub.T and small energy level difference E.sub.ST, which is conducive to reverse intersystem crossing and achieving higher luminescence efficiency. The organic compound molecule has high stability and low stacking degree, which is conducive to reducing concentration quenching and has excellent thermal and film stability. The organic compound is suitable as TADF materials, which is use for OLED devices, conducive to preparing OLED devices, can improve luminescence efficiency and stability of devices, reduce turn-on voltage and extend lifetime of devices.

Provided are an organometallic compound, an organic light-emitting device including the organometallic compound, and an organic light-emitting apparatus including the organic light-emitting device. Organic light-emitting devices including the organometallic compound may have a low driving voltage, high efficiency, and high luminance, thereby implementing high-quality organic light-emitting devices and organic light-emitting apparatuses.

An organic light-emitting display device includes: a plurality of pattern electrodes; a hole-transporting layer disposed on the plurality of pattern electrodes; a plurality of emission layers disposed on the hole-transporting layer and overlapping the plurality of pattern electrodes, respectively; a common electrode disposed on the emission layers; and a first auxiliary layer disposed between a first one of the pattern electrodes and a first one of the emission layers, wherein the first emission layer forms an interface with the hole-transporting layer or the first auxiliary layer, the interface having a hole barrier equal to or less than about 0.1 eV, wherein the hole-transporting layer and the first auxiliary layer have a hole mobility equal to or less than about 1.010.sup.3 cm.sup.2/V.Math.s.

An organic compound, represented by formula [1] or [2], suitably used for a thermally activated delayed fluorescent device: ##STR00001## where X.sub.1 to X.sub.18 and X.sub.21 to X.sub.38 are each independently selected from the group consisting of a hydrogen atom, and substituents, Y is oxygen, sulfur, selenium, tellurium, a CR.sub.1R.sub.2 group, or a carbonyl group, where R.sub.1 and R.sub.2 are each independently selected from the group consisting of a hydrogen atom, and substituents, and Z is an alkyl group, an aryl group, or a heterocyclic group.

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

Disclosed is an organic electroluminescence device. The device includes an anode; a cathode; and a first light-emission layer disposed between the anode and the cathode and configured for emitting blue light. The first light-emission layer comprises a host composition and a blue dopant. The blue dopant includes at least one compound represented by Chemical Formula D. The host composition contains a first host compound and a second host compound. The first host compound has a triplet energy level higher than a triplet energy level of the blue dopant, while the second host compound has a triplet energy level lower than the triplet energy level of the blue dopant. ##STR00001## In Chemical Formula D, each of R.sub.a, R.sub.b, R.sub.c, R.sub.d and R.sub.e independently is the same as defined in the present specification.

A compound represented by the following general formula is an excellent light-emitting material. R.sup.1 to R.sup.5 each independently represent a hydrogen atom or a substituent, and one of R.sup.1 to R.sup.5 is a cyano group, one to three of R.sup.1 to R.sup.5 each are an aryl group Ar optionally substituted with an alkyl group or an aryl group, and one to three of R.sup.1 to R.sup.5 each are a donor group D (but excepting one that corresponds to Ar).

A light-emitting device includes a first electrode; a second electrode facing the first electrode; and an interlayer disposed between the first electrode and the second electrode. The interlayer includes an emission layer and a hole transport region disposed between the first electrode and the emission layer. The hole transport region includes a hole injection layer and a hole transport layer disposed between the hole injection layer and the emission layer. The hole injection layer includes a first compound, the hole transport layer includes a second compound, and a glass transition temperature of the first compound is lower than a glass transition temperature of the second compound.

An organic luminescence device includes a polycyclic compound represented by Formula 1 in at least one functional layer between a first electrode and a second electrode, wherein in Formula 1, X is O, S, Se, CR.sub.4R.sub.5, SiR.sub.6R.sub.7, or ##STR00001##
and at least one selected from L.sub.1 and Ar.sub.1 is an electron withdrawing group having a Hammett constant greater than 0: ##STR00002##

An organic electroluminescence device includes a first electrode and a second electrode facing each other, and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one of the plurality of organic layers includes a fused polycyclic compound represented by Formula 1, and the device exhibits improved luminous efficiency. ##STR00001##