An organic light emitting diode includes a first electrode; a second electrode facing the first electrode; and a first emitting material layer including a first compound and a second compound and positioned between the first and second electrodes. The emission spectrum of the first compound and the absorption spectrum of the second compound has a relatively large overlapping ratio. An organic light emitting device includes the organic light emitting diode and can be a display device or a lighting device.

A light emitting device of an embodiment includes a first electrode, a second electrode oppositely disposed to the first electrode, and an emission layer disposed between the first electrode and the second electrode. The emission layer includes a first host represented by Formula H-1, a second host represented by Formula H-2, and a first dopant represented by Formula 1, wherein Formulas H-1, H-2, and 1 are explained in the specification. The light emitting device shows improved emission efficiency properties.

Provided are a heterocyclic compound represented by Formula 1, an organic light-emitting device including the same, and an electronic apparatus including the organic light-emitting device:

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The substituents in Formula 1 are the same as described in the detailed description.

An organic light emitting diode and an organic light emitting device including the same are discussed. The organic light emitting diode can include a first compound represented by a following formula, a second compound as a p-type host, and a third compound as an n-type host in an emitting material layer. As a result, the organic light emitting diode and the organic light emitting device have advantages in the driving voltage, the luminous efficiency and the lifespan.

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

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is provided. In Formula I, moiety A is a heterocyclic fused ring system comprising a 5-membered ring fused to a 6-membered ring; moiety B is an aromatic ring or fused ring system; each R.sup.A and R.sup.B is independently a hydrogen or a General Substituent; K is a direct bond, O, or S; at least one of R.sup.A and R.sup.B comprises a substituent R comprising a silyl group or a germyl group; ligand L.sub.A is coordinated to a metal M, which has an atomic mass of at least 40; and metal M may be coordinated to other ligands Formulations, OLEDs, and consumer products containing the same are also provided.

Provided are a light-emitting device including a heterocyclic compound represented by Formula 1 below and an electronic apparatus including the light-emitting device. The detailed description of Formula 1 is the same as described in the present specification.

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A light-emitting that includes a first electrode, a second electrode on the first electrode, and at least one functional layer between the first electrode and the second electrode is provided. At least one functional layer may include an aromatic compound represented by Formula 1. The light-emitting element results in a reduced driving voltage and an improved luminous efficiency.

##STR00001##

A light-emitting that includes a first electrode, a second electrode on the first electrode, and at least one functional layer between the first electrode and the second electrode is provided. At least one functional layer may include an aromatic compound represented by Formula 1. The light-emitting element results in a reduced driving voltage and an improved luminous efficiency.

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An organometallic compound, represented by Formula 1:

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

wherein Ln.sub.1 is a ligand represented by Formula 1A, Ln.sub.2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2:

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wherein ring CY.sub.21 is a 5-membered carbocyclic group or a 5-membered heterocyclic group, X.sub.31 and X.sub.32 are each independently O or S, b20 is an integer from 0 to 6, R.sub.11 to R.sub.18, R.sub.20 to R.sub.22, and R.sub.31 to R.sub.37 are as defined herein, and * and *′ each indicates a binding site to M.sub.1.

An organometallic compound represented by Formula 1:

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

wherein, Ln.sub.1 is a ligand represented by Formula 1A, Ln.sub.2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2,

##STR00001##

wherein ring CY.sub.1 and ring CY.sub.2 are each independently a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, ring CY.sub.41 is a benzene group, ring CY.sub.42 is a 5-membered aromatic heterocyclic group, X.sub.1 is C or N, X.sub.2 is C or N, Y.sub.1 is O, S, Se, C(R.sub.3)(R.sub.4), N(R.sub.3), or B(R.sub.3), and R.sub.1 to R.sub.4, R.sub.10, R.sub.20, R.sub.31 to R.sub.34, R.sub.40, b10, b20, and b40 are as described herein.