Alight-emitting element includes an anode electrode, a cathode electrode, a light-emitting layer, a positive hole transport layer, and an electron transport layer. The light-emitting layer, the positive hole transport layer, and the electron transport layer are provided between the anode electrode and the cathode electrode. The light-emitting layer includes QD phosphor particles, a positive hole transport substance configured to transport positive holes transported thereto by the positive hole transport layer, an electron transport substance configured to transport electrons transported thereto by the electron transport layer, and a photosensitive host material.

Disclosed is an organic light-emitting device including an emission layer that includes a first compound.

A light-emitting element includes, in sequence, an anode, a hole transport layer, a luminous layer containing a plurality of quantum dots, an electron transport layer, and a cathode. The electron transport layer includes a plurality of inorganic nanoparticles having electron transportability, and an organic layer having electron transportability. The organic layer partly contains the plurality of inorganic nanoparticles, and includes a plurality of first hollows in an interface adjacent to the luminous layer. The plurality of first hollows are filled with the plurality of quantum dots.

An electronic device includes a base layer and a display element layer including a pixel definition layer having an opening defined therethrough, a light emitting element, and a light receiving element. Each of the light emitting element and the light receiving element includes a first electrode, a hole transport region disposed on the first electrode, an electron transport region disposed on the hole transport region, and a second electrode disposed on the electron transport region. The light emitting element includes a light emitting layer disposed between the hole transport region and the electron transport region. The light receiving element includes a light receiving layer disposed between the hole transport region and the electron transport region and an electron extraction layer, including an n-dopant material, disposed between the light receiving layer and the electron transport region. The light receiving element converts a light incident thereto into an electrical signal.

An organometallic compound represented by Formula 1:

##STR00001## wherein, in Formula 1, groups and variables are the same as described in the specification.

Provided is a light-emitting element with high external quantum efficiency and a low drive voltage. The light-emitting element includes a light-emitting layer which contains a phosphorescent compound and a material exhibiting thermally activated delayed fluorescence between a pair of electrodes, wherein a peak of a fluorescence spectrum and/or a peak of a phosphorescence spectrum of the material exhibiting thermally activated delayed fluorescence overlap(s) with a lowest-energy-side absorption band in an absorption spectrum of the phosphorescent compound, and wherein the phosphorescent compound exhibits phosphorescence in the light-emitting layer by voltage application between the pair of electrodes.

The present invention includes novel platinum complexes with tridentate ligands forming dimeric structures that are calculated to have blue emission. The ligand backbone and pendant donor rings can be altered to give different emission maxima. The present invention also includes various pendant donor rings and multiple different ligand backbones. Such complexes are suitable for use as an emitter in organic light emitting devices.

A composition including a platinum-containing organometallic compound, a first compound, a second compound, and a third compound, and an organic light-emitting device including the same wherein the composition does not comprise iridium, the Pt-containing organometallic compound, the first compound, the second compound, and the third compound are different from each other, the first compound comprises at least one electron transport moiety, the second compound and the third compound do not include a metal, each of an absolute value of a HOMO energy level of the second compound and an absolute value of a HOMO energy level of the third compound is 5.30 eV to 5.85 eV, the difference between the absolute value of the HOMO energy level of the second compound and the absolute value of the HOMO energy level of the third compound is 0.01 eV to 0.30 eV.

An electroluminescent device and a display device including the same are disclosed, wherein the electroluminescent device includes a first electrode; a hole transport layer disposed on the first electrode; a light emitting layer including a first light emitting layer disposed on the hole transport layer, the first emitting layer including a first quantum dot, and a second light emitting layer including a second quantum dot and an n-type organic semiconductor, the second light emitting layer disposed on the first light emitting layer; an electron transport layer disposed on the second light emitting layer; and a second electrode disposed on the electron transport layer.

Provided is a light-emitting element with high external quantum efficiency and a low drive voltage. The light-emitting element includes a light-emitting layer which contains a phosphorescent compound and a material exhibiting thermally activated delayed fluorescence between a pair of electrodes, wherein a peak of a fluorescence spectrum and/or a peak of a phosphorescence spectrum of the material exhibiting thermally activated delayed fluorescence overlap(s) with a lowest-energy-side absorption band in an absorption spectrum of the phosphorescent compound, and wherein the phosphorescent compound exhibits phosphorescence in the light-emitting layer by voltage application between the pair of electrodes.