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.

A light-emitting element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

The present specification relates to an organic light emitting device, a method for manufacturing the same, and a composition for an organic material layer.

Specific polycyclic compounds, a material for an organic electroluminescence device comprising said specific polycyclic compound, an organic electroluminescence device comprising said specific polycyclic compound, an electronic equipment comprising said organic electroluminescence device, a process for preparing said polycyclic compounds, and the use of said polycyclic compounds in an organic electroluminescence. (Formula I) (I)

##STR00001##

A light-emitting element containing a light-emitting material with high light emission efficiency is provided. The light-emitting element includes a high molecular material and a guest material. The high molecular material includes at least a first high molecular chain and a second high molecular chain. The guest material has a function of exhibiting fluorescence or converting triplet excitation energy into light emission. The first high molecular chain and the second high molecular chain each include a first skeleton, a second skeleton, and a third skeleton, and the first skeleton and the second skeleton are bonded to each other through the third skeleton. The first high molecular chain and the second high molecular chain have a function of forming an excited complex.

Using a perovskite-type compound, an inexpensive host material having a high carrier mobility can be provided. Using a perovskite-type compound as a host material, an inexpensive organic light-emitting device having a high emission efficiency can be realized.

The present invention is to provide a photoelectric conversion element with an excellent sensitivity, an imaging element, an optical sensor, and a compound. The photoelectric conversion element according to the embodiment of the present invention includes, in the following order, a conductive film, a photoelectric conversion film, and a transparent conductive film, in which the photoelectric conversion film contains a compound represented by Formula (1) and a coloring agent.

A-D-A  (1)

A light emitting element includes a first electrode, a second electrode disposed on the first electrode, and an emission part disposed between the first electrode and the second electrode and including a first emission layer and a second emission layer disposed on the first emission layer, the first emission layer may include a first host, and a first dopant, and the second emission layer may include a hole transport host different from the first host, an electron transport host, and a second dopant. A first hole mobility of the first host may be in a range of about 5.0×10.sup.−6 cm.sup.2/Vs to about 1.0×10.sup.−3 cm.sup.2/Vs, a second hole mobility of a host mixture including the hole transport host and the electron transport host may be in a range of about 1.0×10.sup.−6 cm.sup.2/Vs to about 1.0×10.sup.−4 cm.sup.2/Vs, and the first hole mobility may be larger than the second hole mobility.

A light-emitting element is provided, including a first electrode and a second electrode, a first layer including first and second organic compounds, the first layer being formed between the first electrode and the second electrode wherein the first organic compound is capable of emitting a first light and the second organic compound has an electron transporting property, and a second layer including third and fourth organic compounds, the second layer being formed between the first layer and the second electrode wherein the third organic compound is capable of emitting a second light and has an electron trap property and the fourth organic compound has an electron transporting property.

Disclosed are an organic compound represented by Chemical Formula 1, and a sensor, a sensor-embedded display panel, and an electronic device including the organic compound.

##STR00001##

In Chemical Formula 1, D, A.sup.1, A.sup.2, R.sup.1, and R.sup.2 are each the same as in the specification.