A display apparatus according to an embodiment of the present disclosure includes a substrate in which an emission area and a non-emission area are divided and a plurality of sub pixels is defined, a first electrode disposed in each of the plurality of sub pixels, a bank which is disposed on an insulating layer above the substrate and exposes the first electrode through an opening, a trench which is formed by removing a partial area of the bank between the plurality of sub pixels to expose the insulating layer, an organic layer disposed above the substrate in which the bank is disposed, a charge blocking layer interposed in the organic layer in the trench, and a second electrode disposed on the organic layer.

A quantum dot white light-emitting diode includes a cathode, an anode, and a light-emitting layer disposed therebetween. The light-emitting layer includes: a blue fluorescent organic layer, a spacer layer, and a quantum dot light-emitting layer. The blue fluorescent organic layer is disposed near the cathode side, the quantum dot light-emitting layer is disposed near the anode side, and the spacer layer is disposed between the blue fluorescent organic layer and the quantum dot light-emitting layer. A material of the quantum dot light-emitting layer contains quantum dots, a material of the blue fluorescent organic layer contains a blue fluorescent organic material, and a material of the spacer layer contains a spacer material. A triplet exciton energy of the spacer material is greater than a triplet exciton energy of the blue fluorescent organic material, and a triplet exciton energy of the spacer material is greater than a quantum dot exciton energy.

A europium-doped β-sialon phosphor particle. When the element concentration of a Si atom on the surface portion of the particle that is obtained by analyzing a cross section of the phosphor particle by the energy dispersive X-ray analysis method is indicated by Ps [at %], and the element concentration of a Si atom near the center of the particle that is obtained by an analysis by the same method is indicated by Pc [at %], the Pc-Ps value is 3 at % or more.

An organic electroluminescence device includes an anode, a cathode, a first emitting layer, and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer contains, as a first host material, a first compound represented by a formula (1) below and having a group represented by a formula (11) below, the second emitting layer contains a second compound represented by one of formulae (2-1D) to (2-4D) below as a second host material, and the first emitting layer is in direct contact with the second emitting layer.

##STR00001## ##STR00002##

Provided is a compound of Chemical Formula 1: ##STR00001## where R.sub.1 and R.sub.2 are each independently hydrogen, a substituted or unsubstituted C.sub.1-60 alkyl, a substituted or unsubstituted C.sub.1-60 alkoxy, a substituted or unsubstituted C.sub.1-60 haloalkyl, a substituted or unsubstituted C.sub.1-60 haloalkoxy, halogen, cyano, tri(C.sub.1-60 alkyl)silyl, a substituted or unsubstituted C.sub.6-60 aryl, or a substituted or unsubstituted C.sub.2-60 heteroaryl containing at least one of O, N, Si and S, R.sub.3 and R.sub.4 are each independently hydrogen, deuterium, a substituted or unsubstituted C.sub.1-60 alkyl, a substituted or unsubstituted C.sub.1-60 alkoxy, a substituted or unsubstituted C.sub.1-60 haloalkyl, a substituted or unsubstituted C.sub.1-60 haloalkoxy, halogen, cyano, tri(C.sub.1-60 alkyl)silyl, or a substituted or unsubstituted C.sub.2-60 heteroaryl containing at least one of O, N, Si and S, and Ar is C.sub.6-60 aryl, or C.sub.2-60 heteroaryl containing at least one of O, N, Si and S, wherein the C.sub.6-60 aryl, or C.sub.2-60 heteroaryl is substituted with 1 to 5 substituents each selected from the group consisting of a substituted or unsubstituted C.sub.1-60 alkyl, a substituted or unsubstituted C.sub.1-60 alkoxy, a substituted or unsubstituted C.sub.1-60 haloalkyl, a substituted or unsubstituted C.sub.1-60 haloalkoxy, halogen, cyano, and tri(C.sub.1-60 alkyl)silyl, and an organic light emitting device including the same.

The embodiments of the present disclosure provide a light-emitting device and a display substrate, which belong to the technical field of organic light-emitting diodes. The light-emitting device of the present disclosure comprises: a first light-emitting layer comprising a first host material and a first guest material; and a second light-emitting layer comprising a second host material and a second guest material; S1(h1)>S1(g1), T1(h1)>T1(g1), S1(g1)−T1(g1)≤0.1 eV; S1(h2)>S1(g2), T1(h2)>T1(g2), S1(g2)−T1(g2)≤0.1 eV; S1(h1)≥S1(h2)>S1(g1)>S1(g2), T1(h1)≥T1(h2)>T1(g1)>T1(g2); the second guest material is a TADF material; at least 40% of the area in a region covered under the emission spectrum of the first light-emitting layer overlaps with the region covered under the absorption spectrum of the second light-emitting layer.

The embodiments of the present disclosure provide a light-emitting device and a display substrate, which belong to the technical field of organic light-emitting diodes. The light-emitting device of the present disclosure comprises: a first light-emitting layer comprising a first host material and a first guest material; and a second light-emitting layer comprising a second host material and a second guest material; S1(h1)>S1(g1), T1(h1)>T1(g1), S1(g1)−T1(g1)≤0.1 eV; S1(h2)>S1(g2), T1(h2)>T1(g2), S1(g2)−T1(g2)≤0.1 eV; S1(h1)≥S1(h2)>S1(g1)>S1(g2), T1(h1)≥T1(h2)>T1(g1)>T1(g2); the second guest material is a TADF material; at least 40% of the area in a region covered under the emission spectrum of the first light-emitting layer overlaps with the region covered under the absorption spectrum of the second light-emitting layer.

The present disclosure relates to an organic light emitting diode that includes a first electrode; a second electrode facing the first electrode; and a first emitting material layer including a first compound and a second compound and positioned between the first and second electrodes, wherein an overlap ratio between an absorption spectrum of the first compound and an emission spectrum of the second compound is equal to or greater than 35%, and an organic light emitting display including the organic light emitting diode.

The present disclosure relates to an organic light emitting diode that includes a first electrode; a second electrode facing the first electrode; and a first emitting material layer including a first compound and a second compound and positioned between the first and second electrodes, wherein an overlap ratio between an absorption spectrum of the first compound and an emission spectrum of the second compound is equal to or greater than 35%, and an organic light emitting display including the organic light emitting diode.

An organic compound is represented by formula [1]. In formula [1], L and L′ are bidentate ligands different from each other, a partial structure IrL.sub.m is a partial structure represented by formula [2], and a partial structure IrL′.sub.n is a partial structure represented by formula [3-1] or formula [3-2].

##STR00001##