An organic electroluminescent device having high efficiency and high driving stability, and a material suitable for the organic electroluminescent device are provided. The material for organic electroluminescent devices comprises an indolocarbazole compound represented by a general formula (1). In the formula, the ring a is represented by a formula (1a), X is NR, S, O or CR.sub.2, and Ar.sup.1 and Ar.sup.2 are an aromatic heterocyclic group represented by a formula (1b). Y is N or CR, and at least one is N. L.sup.1 is an aromatic hydrocarbon group. The material for the organic electroluminescent devices is suitable as material for the host of the light emitting layer or the hole blocking layer of organic EL devices.

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A near-infrared organic EL device with favorable efficiency is provided. A light-emitting device including a first electrode, a second electrode, and an EL layer is provided; in which the EL layer is positioned between the first electrode and the second electrode; in which the EL layer emits light having a peak of an emission spectrum in a wavelength range of greater than or equal to 750 nm and less than or equal to 1000 nm; in which one of the first electrode and the second electrode is an electrode having a transmitting property with respect to light with a peak wavelength of the emission spectrum of the EL layer; in which a first layer is provided in contact with a surface of the electrode having a transmitting property, which is opposite to a surface facing the EL layer; in which the first layer contains an organic compound; and in which the first layer has the local maximum value of an extinction coefficient k in the visible light region.

A compound represented by the following formulas (1-1) and (1-3), or a compound represented by the following formulas (1-2) and (1-3). At least one of R.sub.1 to R.sub.16 is a substituted or unsubstituted alkyl group including 1 to 50 carbon atoms or the like. In the compound represented by the formulas (1-1) and (1-3), at least one of R.sub.5 to R.sub.7 and R.sub.14 to R.sub.16 is —N(R.sub.36)(R.sub.37), and in the compound represented by the formulas (1-2) and (1-3), at least one of R.sub.2 to R.sub.16 is —N(R.sub.36)(R.sub.37).

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Provided are a composition for an organic optoelectronic device including a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2, an organic optoelectronic device including the same, and a display device. Details of Chemical Formula 1 and Chemical Formula 2 are as defined in the specification.

Disclosed herein are a novel organometallic compound and an organic light-emitting diode including same. More specifically, an organometallic compound represented by [Chemical Formula 1] and an organic light-emitting diode including same are provided.

An organic electroluminescence device comprising: a cathode; an anode; an emitting layer disposed between the cathode and the anode; and a first layer disposed between the emitting layer and the cathode, wherein the emitting layer comprises a host compound, the first layer comprises a first compound and a second compound, and the three compounds are in a relationship satisfying the following Conditions 1 and 2: (Condition 1) the electron affinity Af.sub.H of the host compound and the electron affinity Af.sub.ETA of the first compound satisfy the following expressions (1-1) and (1-2):

Af.sub.H<Af.sub.ETA  (1-1)

|Af.sub.H−Af.sub.ETA|≤0.10  (1-2) (Condition 2) the electron affinity Af.sub.H of the host compound and the electron affinity Af.sub.ETB of the second compound satisfy the following expressions (2-1) and (2-2):

Af.sub.H>Af.sub.ETB  (2-1)

|A.sub.fH−Af.sub.ETB|≤0.10  (2-2).

Provided is an organometallic compound of Chemical Formula 1: ##STR00001## wherein, in Chemical Formula 1: X is O, S, NH, or Se; R.sub.1 is —Si(R.sub.a)(R.sub.b)(R.sub.c), where R.sub.a, R.sub.b, and R.sub.c are hydrogen, deuterium, or a substituted or unsubstituted C.sub.1-10 alkyl; R.sub.2, R.sub.3 and R.sub.4 are each independently hydrogen, deuterium, halogen, cyano, amino, a substituted or unsubstituted C.sub.1-60 alkyl, a substituted or unsubstituted C.sub.1-60 haloalkyl, a substituted or unsubstituted C.sub.1-60 alkoxy, a substituted or unsubstituted C.sub.1-60 haloalkoxy, a substituted or unsubstituted C.sub.3-60 cycloalkyl, a substituted or unsubstituted c.sub.2-60 alkenyl, a substituted or unsubstituted C.sub.6-60 aryl, a substituted or unsubstituted C.sub.6-60 aryloxy, or a substituted or unsubstituted C.sub.2-60 heterocyclic group containing one or more heteroatoms selected from the group consisting of N, O and S; a and b are each 0 and 1, or 1 and 0, respectively; and n is 1 or 2,
and an organic light emitting device including the same.

An organic electroluminescence device of one or more embodiments includes a first electrode, a hole transport region on the first electrode, an emission layer on the hole transport region, an electron transport region on the emission layer and a second electrode on the electron transport region, wherein the hole transport region includes a monoamine compound represented by Formula 1, thereby showing high emission efficiency: ##STR00001##

An organic electroluminescence device comprising: a cathode, an anode, and at least one organic layer disposed between the cathode and the anode, wherein at least one layer of the at least one organic layer comprises a compound represented by the following formulas (1-1) and (1-3) or a compound represented by the following formulas (1-2) and (1-3). ##STR00001##

The present disclosure provides an organic light emitting diode comprising a first electrode; a second electrode facing the first electrode; and an emitting material layer. The emitting material layer includes a p-type host, a n-type host and a phosphorescent dopant and positioned between the first electrode and the second electrode, wherein a first energy level of a HOMO of the p-type host is equal to or lower than a second energy level of a HOMO of the n-type host, and a difference between an energy level of a singlet state of the n-type host and an energy level of a triplet state of the n-type host is greater than 0.3 eV and smaller than 0.5 eV.