A light emitting diode of an embodiment includes a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. The hole transport region includes a first hole transport layer disposed adjacent to the first electrode and having a first refractive index, a second hole transport layer disposed adjacent to the emission layer and having a second refractive index, and a third hole transport layer disposed between the first hole transport layer and the second hole transport layer and having a third refractive index which is greater than each of the first refractive index and the second refractive index, thereby showing high light extraction efficiency and high emission efficiency properties.

A compound of Formula 1, as disclosed herein, is useful in an organic light emitting device and apparatuses including the same.

Provided is an organic light-emitting device including a light-emitting layer comprising a compound of Chemical Formula 1, and a first organic material layer comprising a compound of Chemical Formula 2:

##STR00001## wherein: Cy1 to Cy5 are each independently one selected from the group consisting of a substituted or unsubstituted: aromatic hydrocarbon ring, aliphatic hydrocarbon ring, and an aromatic hetero ring, or a ring in which two or more rings selected from the above group are fused, one or more of Cy1 to Cy5 are a ring of the following Chemical Formula 1-A,

##STR00002##

wherein: Ar1 and Ar2 are the same as or different from each other, and are each independently a phenyl, a biphenyl, a terphenyl, a naphthyl, a phenanthrenyl, or a triphenylenyl, where the naphthyl, phenanthrenyl, and triphenylenyl can be substituted with a phenyl.

A light emitting diode of one or more embodiments includes a first electrode, a second electrode opposite the first electrode, and at least one functional layer disposed between the first electrode and the second electrode, the at least one functional layer including a polycyclic compound represented by Formula 1 below, wherein the first electrode and the second electrode each independently includes at least one selected from among Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, Zn, compounds thereof, and mixtures thereof.

##STR00001##

The present application provides a heterocyclic compound capable of significantly enhancing lifetime, efficiency, electrochemical stability and thermal stability of an organic light emitting device, and an organic light emitting device including the heterocyclic compound in an organic material layer.

The present disclosure features a luminescent molecule, including a luminophore (e.g., a fluorescent dye); and a moiety including a heteroaryl core covalently and directly bonded to the luminophore. The luminescent molecule has an increased photoluminescence quantum yield relative to an analogous luminophore without a covalently bonded moiety including the heteroaryl core.

Disclosed herein is an organic light-emitting diode, comprising: a first electrode; a second electrode facing the first electrode; and an electron-blocking layer and a light-emitting layer sequentially interposed between the first electrode and the second electrode, wherein the light-emitting layer comprises at least one of the amine compounds represented by the following Chemical Formula A or B, and the electron-blocking layer comprises the compound represented by the following Chemical Formula C. Chemical Formulas A, B and C are as described in the Specification.

A nitrogen-containing compound as shown in Chemical formula (1), an electronic element, and an electronic device are provided. In Chemical formula (1), Ar.sub.1 and Ar.sub.2 are selected from a substituted or unsubstituted C6 to C30 aryl, a substituted or unsubstituted C3 to C30 heteroaryl, or a substituted or unsubstituted C3 to C20 cycloalkyl; Ar.sub.3 is selected from a substituted or unsubstituted C6 to C20 aryl, or a substituted or unsubstituted C3 to C20 heteroaryl.

##STR00001##

An objective of the disclosure is to provide an organic light-emitting composite material based on an exciplex, which, when used as a light-emitting layer, can enhance the efficiency of an organic electroluminescent device. The disclosure also relates to an organic light-emitting device comprising the organic light-emitting composite material, and use of the organic light-emitting composite material of the disclosure for an organic electron device.

The present specification relates to an ink composition including: a compound represented by Formula 1; and a solvent represented by the Formula 2, and a method for manufacturing an organic light emitting device formed by using the ink composition.