An organometallic compound is represented by Formula 1. An organic light-emitting device includes a first electrode, a second electrode, and an organic layer including an emission layer between the first electrode and the second electrode, wherein the organic layer includes at least one of the organometallic compound represented by Formula 1. An apparatus includes the organic light-emitting device.

A solar cell 100 includes a substrate 1, a first electrode 6, an electron transport layer 2, a first photoelectric conversion layer 3, and a coating layer 5. The first photoelectric conversion layer 3 is disposed between the first electrode 6 and the substrate 1. The substrate 1 has a first main surface and a second main surface, and the second main surface has an uneven structure. The electron transport layer 2 has a first main surface and a second main surface, and the first main surface and the second main surface each have an uneven structure. The first photoelectric conversion layer 3 has a first main surface and a second main surface. The second main surface of the substrate 1 faces the first main surface of the electron transport layer 2.

A synchronized piezoelectric and luminescence (SPL) material includes a core layer including light-emitting particles and a shell layer which is attached onto a surface of the core layer and includes ligands having a piezoelectric property. Therefore, a piezoelectric property and a luminescent property can be simultaneously implemented using a single SPL material in which piezoelectric ligands and light-emitting particles are chemically coupled.

A synchronized piezoelectric and luminescence (SPL) material includes a core layer including light-emitting particles and a shell layer which is attached onto a surface of the core layer and includes ligands having a piezoelectric property. Therefore, a piezoelectric property and a luminescent property can be simultaneously implemented using a single SPL material in which piezoelectric ligands and light-emitting particles are chemically coupled.

Disclosed is an organometallic compound represented by a following Chemical Formula I, wherein the compound is a metal complex including a central coordination metal and a main ligand binding thereto, wherein the main ligand has a structure in which a fused ring is further introduced into 2-phenylquinoline. When the organometallic compound is used as dopant of a light-emitting layer of an organic electroluminescent device, rigidity is imparted to the organometallic compound molecule such that a full width at half maximum (FWHM) is narrow and thus color purity is improved. Further, a non-luminescent recombination process is reduced such that luminous efficiency and lifespan of the organic electroluminescent device are improved. Chemical Formula I is shown below:

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The present disclosure relates to a plurality of host materials comprising a first host material including a compound represented by formula 1 and a second host material including a compound represented by formula 2, and an organic electroluminescent device comprising the same. In addition, the present disclosure relates to an organic electroluminescent compound, and an organic electroluminescent device comprising the same. By comprising the organic electroluminescent compound and/or a specific combination of compounds according to the present disclosure as host materials, an organic electroluminescent device having high luminous efficiency and long lifespan property can be provided.

An aspect of the present disclosure is a method that includes combining a first organic salt (A.sup.1X.sup.1), a first metal salt (M.sup.1(X.sup.2).sub.2), a second organic salt (A.sup.2X.sup.3), a second metal salt (M.sup.2Cl.sub.2), and a solvent to form a primary solution, where A.sup.1X.sup.1 and M.sup.1(X.sup.2).sub.2 are present in the primary solution at a first ratio between about 0.5 to 1.0 and about 1.5 to 1.0, and A.sup.2X.sup.3 to M.sup.2Cl.sub.2 are present in the primary solution at a second ratio between about 2.0 to 1.0 and about 4.0 to 1.0. In some embodiments of the present disclosure, at least one of A.sup.1 or A.sup.2 may include at least one of an alkyl ammonium, an alkyl diamine, cesium, and/or rubidium.

[Problem] Provided are a photoelectric conversion device and an imaging apparatus capable of improving quantum efficiency and a response speed. [Solving means] A first photoelectric conversion device according to one embodiment of the present disclosure includes a first electrode, a second electrode opposed to the first electrode, and a photoelectric conversion layer. The photoelectric conversion layer is provided between the first electrode and the second electrode and includes at least one type of one organic semiconductor material having crystallinity. Variation in a ratio between horizontally-oriented crystal and vertically-oriented crystal in the photoelectric conversion layer is three times or less between a case where film formation of the one organic semiconductor material is performed at a first temperature and a case where the film formation of the one organic semiconductor material is performed at a second temperature. The second temperature is higher than the first temperature.

To provide an n-type dopant capable of providing high charge mobility and controlling the Fermi level. To provide an organic semiconductor layer having high charge mobility, no crystal distortion, no dopant diffusion even at high temperatures, and having a controlled Fermi level. To provide an organic semiconductor devices such as an organic semiconductor solar cells with high power conversion efficiency.

An n-type organic semiconductor layer, in which ionic atom encapsulated fullerene neutral substance is doped in a layer made of fullerene. The n-type semiconductor layer is an electron transport layer. N-type dopant including ionic atom encapsulated fullerene neutral substance doped in an organic semiconductor layer.

The present specification relates to a compound represented by Chemical Formula 1, a composition for forming an optical film and an optical film comprising the same, and a display device comprising the optical film.