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 a specific chemical structure. Accordingly, the light emitting element exhibits a high color purity, a low driving voltage, a long service life, and a high efficiency.

Provided are a triarylamine derivative and an organic electroluminescent device thereof, which relate to the technical field of organic electroluminescence. The triarylamine derivative has a relatively high triplet energy level, high hole mobility, a high refractive index and good film formability and thermal stability and can effectively reduce the driving voltage of the organic electroluminescent device, improve the luminescence efficiency, and extend the service life of the device when applied to the organic electroluminescent device. The triarylamine derivative has a good application effect and a good industrialization prospect in the organic electroluminescent device.

A compound represented by the following formula (1):

##STR00001##

The R.sup.1 to R.sup.9, L.sup.1 to L.sup.3, and Ar.sup.1 to Ar.sup.2 in the formula (1) are as defined in the description. An organic electroluminescence device contains the compound, and an electronic instrument includes the organic electroluminescence device.

A compound comprising a first ligand L.sub.A of Formula I

##STR00001##

is described. In Formula I, X.sup.1 and X.sup.6 to X.sup.10 are each independently C or N; X.sup.2 is CR.sup.1′ or N; X.sup.3 is CR.sup.1 or N; X.sup.4 is CR.sup.2 or N; X.sup.5 is CR.sup.3 or N; each R.sup.1, R.sup.2, R.sup.3, R.sup.A, R.sup.B, and R.sup.C is independently a hydrogen or a General Substituent; any two substituents may be joined or fused to form a ring; at least one of R.sup.1′, R.sup.1, R.sup.2, and R.sup.3 is a partially or fully deuterated alkyl or cycloalkyl group; at least one pair of R.sup.C are joined or fused to form a 5-membered or 6-membered ring. Formulations, OLEDs, and consumer products comprising the compound are also described.

A composition including a first compound and a second compound, wherein the first compound is an organometallic compound including platinum and a tetradentate ligand bound thereto, and the second compound is an organometallic compound including iridium, μ(Pt) is about 0.5 debye to about 5.0 debye, μ(Pt) is less than μ(Ir), μ(Pt) is a dipole moment of the first compound, μ(Ir) is a dipole moment of the second compound, and each of μ(Pt) and μ(Ir) is calculated based on density functional theory as described herein.

An organometallic compound, represented by Formula 1:

M.sub.1(Ln.sub.1).sub.n1(Ln.sub.2).sub.n2  Formula 1

wherein, in Formula 1, M.sub.1 is a transition metal, Ln.sub.1 is a ligand represented by Formula 1-1, Ln.sub.2 is a ligand represented by Formula 2-1 or 2-2, n1 is 1 or 2, and n2 is 1 or 2:

##STR00001## wherein, in Formulae 1-1, 2-1, and 2-2, CY.sub.1, X.sub.21 to X.sub.28, X.sub.31, X.sub.32, R.sub.10, R.sub.31 to R.sub.37, R.sub.41 to R.sub.44, and b10 are as defined herein, and * and *′ each indicates a binding site to M.sub.1.

An organoelectroluminescent device according to the present invention is capable of low voltage driving, has an excellent external quantum efficiency and exhibits highly efficient light-emitting characteristics by employing compounds having distinct structures, as a hole transport material and a dopant material, in a hole injection layer or a hole transport layer, and a light-emitting layer, respectively, and thus can be industrially utilized in a flat display device, a flexible display device, a monochrome or white flat panel lighting apparatus, a monochrome or white flexible lighting apparatus and the like.

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.

##STR00001##

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.

##STR00001##

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