An organic electroluminescent device is disclosed. The organic electroluminescent device includes a light-emitting layer that contains a plurality of hosts and dopants, where one of the plurality of hosts includes the same material as in an electron transport auxiliary layer in an electron transport region, whereby the organic electroluminescent device simultaneously exhibits effects such as low driving voltage, high luminous efficiency, and a long lifespan.

The present invention relates to organic electroluminescent devices, the emitting layer thereof containing a blend of a luminescent material having a narrow singlet-triplet gap and a fluorescent emission material having high steric shielding.

A composition formed of a mixture of two compounds having similar thermal evaporation properties that are pre-mixed into an evaporation source that can be used to co-evaporate the two compounds into an emission layer in OLEDs via vacuum thermal evaporation process is disclosed.

The present invention describes amines with dibenzofuran, dibenzothiophene and fluorene groups, especially for use as triplet matrix materials in organic electroluminescent devices. The invention further relates to a process for preparing the compounds of the invention and to electronic devices comprising these.

The present invention includes novel compounds containing deuterated or partially deuterated xanthene and thioxanthene structures. These compounds may be useful as host materials with high triplet energies for phosphorescent electroluminescent devices.

An organometallic compound including a first ligand L.sub.A selected from

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is provided. In ligand L.sub.A, each of Y.sup.1 to Y.sup.10 is carbon or nitrogen; moiety B is a monocyclic or polycyclic fused ring structure comprising 5-membered and/or 6-membered rings; any two R.sub.A and R.sub.B can be fused or joined to form a ring; X is selected from O, S, Se, or NR; each R.sub.A and R.sub.B is independently hydrogen or a General Substituent; at least one R, R.sub.A, or R.sub.B is deuterium or a linking group between L.sub.A and another ligand that includes a deuterium substituted aromatic ring; and L.sub.A is coordinated to a metal M, selected from Os, Pd, Pt, Ir, Cu, Ag, or Au; and the compound is capable of emitting light with a peak maximum wavelength (λ.sub.max)≥700 nm at room temperature.

The present disclosure provides a thermally activated delayed fluorescent material and application thereof, the thermally activated delayed fluorescent material is a compound having a structure represented by Formula I and can be used as a light-emitting layer material of an organic electroluminescent device. The thermally activated delayed fluorescent material is applied to an organic electroluminescent device comprising an anode, a cathode, and at least one organic thin film layer between the anode and the cathode, the light-emitting layer in the organic thin film layer comprises any one or a combination of at least two of the thermally activated delayed fluorescent materials. An energy level difference between the triplet state and the singlet state of the thermally activated delayed fluorescent material provided by the present disclosure can be reduced to below 0.25 eV, and when used as a light-emitting layer material in an organic electroluminescent device, it can improve carrier balance, increase luminous efficiency, and reduce the device's voltage.

A light-emitting device includes: 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 first emission layer and a second emission layer contacting each other, the first emission layer includes a first host and a first dopant, the second emission layer includes a second host and a second dopant, the first dopant includes a fluorescent dopant, the second dopant includes a phosphorescent dopant, a triplet energy level of the first host is lower than a triplet energy level of the first dopant, and a triplet energy level of the second host is higher than a triplet energy level of the second dopant.

An organometallic compound represented by Formula 1:

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wherein Ln.sub.1 is a ligand represented by Formula 1A, Ln.sub.2 is a ligand represented by Formula 1B, X.sub.1 is O, S, or Se, CY.sub.1 is a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, n1 is 1 or 2, n2 is 1, 2, or 3, and the remaining substituents are as defined in the present specification.

A light-emitting device including a heterocyclic compound represented by Formula 1 and a phosphorescent dopant, and an electronic apparatus including the light-emitting device are provided. Formula 1 is the same as described in the present specification. The light-emitting device includes: a first electrode, a second electrode facing the first electrode, an interlayer between the first electrode and the second electrode and including an emission layer, and the heterocyclic compound represented by Formula 1.

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