Disclosed herein are a novel organometallic compound and an organic light-emitting diode including same. More specifically, an organometallic compound represented by [Chemical Formula 1] and an organic light-emitting diode including same are provided.

The present disclosure provides an organic light emitting diode comprising a first electrode; a second electrode facing the first electrode; and an emitting material layer. The emitting material layer includes a p-type host, a n-type host and a phosphorescent dopant and positioned between the first electrode and the second electrode, wherein a first energy level of a HOMO of the p-type host is equal to or lower than a second energy level of a HOMO of the n-type host, and a difference between an energy level of a singlet state of the n-type host and an energy level of a triplet state of the n-type host is greater than 0.3 eV and smaller than 0.5 eV.

An organic electric element according to an embodiment of the present disclosure includes a first electrode, a second electrode, and an organic material layer formed between the first electrode and the second electrode. The organic material layer includes a plurality of emission-auxiliary layers, and the HOMO energy levels of the plurality of emission-auxiliary layers are limited to specific conditions in relation to the neighboring organic material layers, thereby the driving voltage, the luminous efficiency and the life time of the organic electric element can be improved.

The present disclosure relates to compounds of Formula (I), (II), or (III) ##STR00001## as compounds capable of emitting delayed fluorescence, and uses of these compounds in organic light-emitting diodes.

The present disclosure provides a composition. In an embodiment, a composition is provided and comprises a Compound 1 shown below: For Compound 1, R.sub.1 through R.sub.24 are the same or different. R.sub.1 through R.sub.24 each is independently selected from the group consisting of hydrogen, unsubstituted hydrocarbyl, substituted hydrocarbyl, cyano, alkoxy, aryloxy, and NR′.sub.2. R′ is hydrogen or hydrocarbyl; wherein two or more of adjacent R.sub.1 to R.sub.24 may optionally form one or more ring structures. The Component Z is selected from the group consisting Group Z-1, Group Z-2, Group Z-3, Group Z-4, Group Z-5, Group Z-6 and Group Z-7 shown below: For Compound 1, one or more hydrogen atoms may optionally be substituted with deuterium.

##STR00001##

In the organic electroluminescent device having at least an anode, a hole injection layer, a first hole injection layer, a second hole injection layer, a light emitting layer, an electron transport layer and a cathode in this order, the hole injection layer includes an arylamine compound of the following general formula (1) and an electron acceptor.

##STR00001##

In the formula, Ar.sub.1 to Ar.sub.4 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group.

A light emitting device including an emissive material comprising quantum dots is disclosed. In one embodiment, the device includes a cathode, a layer comprising a material capable of transporting and injection electrons comprising an inorganic material, an emissive layer comprising quantum dots, a layer comprising a material capable of transporting holes, a layer comprising a hole injection material, and an anode. In certain embodiments, the hole injection material can be a p-type doped hole transport material. In certain preferred embodiments, quantum dots comprise semiconductor nanocrystals. In another aspect of the invention, there is provided a light emitting device wherein the device has an initial turn-on voltage that is not greater than 1240/λ, wherein λ represents the wavelength (nm) of light emitted by the emissive layer. Other light emitting devices and a method are disclosed.

The present invention provides an organic electroluminescent element which comprises: an anode; a cathode; and an organic layer interposed between the anode and the cathodes, wherein the organic layer comprises one or more types of layer from the group consisting of a hole-injection layer, hole-transport layer, light-emitting layer, lifetime enhancement layer, electron-transport layer, and electron-injection layer.

A thermally activated, sensitized phosphorescence organic electroluminescence device includes a luminescent layer formed of a host material consisting of two materials, one being a hole transport material, and the other an electron transport material, at least one which is a thermally activated delayed fluorescence material. The host material is doped by a phosphorescent dye. The triplet state energy level of the CT excited state of the fluorescence material is higher than the triplet state energy level of the n-π excited state by 0 to 0.3 or the triplet state energy level of the CT excited state of the fluorescence material is higher than the triplet state energy level of the n-π excited state, wherein the difference is above 1.0 eV, and, a difference between the second triplet state energy level of its n-π excited state and the first singlet state energy level of its CT excited state is −0.1 to 0.1 eV.

An organic light-emitting display panel and an organic light-emitting display device are disclosed, wherein the organic light-emitting display panel includes: a substrate, a cathode, a first auxiliary functional structure, a light-emitting structure and an anode that are successively laminated; wherein, the material of both the anode and the cathode is silver or a silver-containing metallic material, and a micro-cavity structure is formed between the cathode and the anode; the first auxiliary functional structure includes at least one of an electron injection layer, an electron transport layer and a hole blocking layer, and the first auxiliary functional structure is multiplexed as a micro-cavity length adjusting structure.