A light emitting element that includes a first electrode, a second electrode on the first electrode, and an emission layer between the first electrode and the second electrode is provided. The emission layer includes an organometallic compound represented by Formula 1. The light emitting element exhibits long lifespan properties.

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A novel display apparatus that is highly convenient, useful, or reliable is provided. The display apparatus includes a first electrode, a second electrode, a first unit, a second unit, and a first intermediate layer; the first unit is located between the second electrode and the first electrode; and the first unit contains a first light-emitting material EM1. The second unit is located between the second electrode and the first unit and contains a second light-emitting material EM2. The first intermediate layer is located between the second unit and the first unit. The first intermediate layer includes a first layer and a second layer; the first layer is located between the second unit and the second layer; the first layer contains an organic compound having a halogen group or a cyano group or a transition metal oxide; and the second layer contains a first organic compound AM2 having an electron-accepting property, a second organic compound DM having an electron-donating property, and a third organic compound BM having basicity.

Provided is a light-emitting device which may include a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a host and a dopant, the host includes a first compound and a second compound, the dopant includes a third compound and a fourth compound, the first compound, the second compound, the third compound, and the fourth compound are different from each other, the third compound is a platinum-containing organometallic compound, the platinum-containing organometallic compound includes platinum and a first ligand bonded to the platinum, the first ligand includes a carbene group, the carbon of the carbene group and the platinum are bonded together, and Expression 1 is satisfied, which is explained in the specification.

A light emitting element that includes a first electrode, a second electrode facing the first electrode, and an emission layer between the first electrode and the second electrode is provided. The emission layer includes a polycyclic compound represented by Formula 1. The light emitting element has a reduced driving voltage and an increased efficiency.

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An asymmetric fused aromatic ring derivative containing sulfonyl group, which includes a structure represented by formula (I). Formula (I) is defined as in the specification. A use of the asymmetric fused aromatic ring derivative containing sulfonyl group, which is used as a photocatalyst. A hydrogen production device, which includes the asymmetric fused aromatic ring derivative containing sulfonyl group. An optoelectronic component, which includes the asymmetric fused aromatic ring derivative containing sulfonyl group.

The present invention relates to organic light emitting elements, comprising thermally activated delayed fluorescence (TADF) emitters and/or hosts of formula ##STR00001##
which have a sufficiently small energy gap between S.sub.1 and T.sub.1 (ΔE.sub.ST) to enable up-conversion of the triplet exciton from T.sub.1 to S.sub.1. The organic light emitting elements show high electroluminescent efficiency.

An organic light-emitting device (OLED) includes a first electrode, a second electrode, an emission layer between the first electrode and the second electrode and including an electron-transporting host and a hole-transporting host, a hole transport region between the first electrode and the emission layer and including a hole transport layer, and an electron transport region between the emission layer and the second electrode and including an electron transport layer, wherein the OLED satisfies Equations 1 and 2 below:
0.75 eV≤|LUMO.sub.H(ET)−LUMO.sub.H(HT)|≤0.90 eV  <Equation 1>
|E(S.sub.1,H(ET))−E(S.sub.1,H(HT))|<0.15 eV  <Equation 2> wherein in Equations 1 and 2, LUMO.sub.H(ET) refers to a lowest unoccupied molecular orbital (LUMO) energy level of the electron-transporting host, LUMO.sub.H(HT) refers to an LUMO energy level of the hole-transporting host, E(S.sub.1, H(ET)) refers to a singlet energy level of the electron-transporting host, and E(S.sub.1, H(HT)) refers to a singlet energy level of the hole-transporting host.

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

Provided are a condensed cyclic compound and an organic light-emitting device including the same. The organic light-emitting device may include a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode. The organic layer may include the condensed cyclic compound represented by Formula 1: ##STR00001## In Formula 1, rings A.sub.1, A.sub.2, and A.sub.3 may each be independently a C.sub.5-C.sub.60 carbocyclic group or a C.sub.2-C.sub.30 heterocyclic group, and n1 to n3 may each be independently 0 or 1, provided that the sum of n1, n2, and n3 is 1. In addition, the descriptions of X.sub.1, L.sub.1 to L.sub.9, a1 to a9, Ar.sub.1 to Ar.sub.6, b1 to b6, R.sub.1 to R.sub.3, and c1 to c3 are as defined in the present specification.

A compound containing indolocarbazole having a formula: ##STR00001##
Formula I is disclosed.