To provide an organic electroluminescent device having high efficiency and high driving stability while having a low driving voltage. The organic electroluminescent device has one or more light-emitting layers between an anode and a cathode opposed to each other, wherein at least one of the light-emitting layers is a light-emitting layer composed of a vapor deposition layer containing a first host, a second host and a light-emitting dopant material; the first host is selected from oligopyridine compounds represented by the general formula (1); and the second host is selected from carbazole compounds having two or more carbazole rings, indolocarbazole compounds having an indolocarbazole ring or compounds having a carbazole ring and an indolocarbazole ring.

A compound of: ##STR00001##
is disclosed. In Formula IV, ring B and ring C are each independently a 5 or 6-membered carbocyclic or heterocyclic ring; A-B represents a bonded pair of carbocyclic or heterocyclic rings coordinated to a metal M via a nitrogen atom in ring A and an sp.sup.2 hybridized atom in ring B; A-C represents a bonded pair of carbocyclic or heterocyclic rings; M is a metal having an atomic number greater than 40; L′ is a monoanionic bidentate ligand; m is the oxidation state of the metal M; and n is at least 1.

A light emitting element includes a first electrode, a second electrode disposed on the first electrode, and a light emitting area disposed between the first electrode and the second electrode and including a phosphorescent dopant, a hole transporting host, and an electron transporting host, wherein the light emitting area includes at least one auxiliary light emitting layer including a thermally activated delayed fluorescence dopant, the hole transporting host, and the electron transporting host and spaced apart from the first electrode and the second electrode.

The present invention relates to spiro compounds containing electron-conducting groups and to electronic devices, in particular organic electroluminescent devices, comprising these compounds.

An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material.

A composition of materials including a first compound having a structure according to Formula I

##STR00001##

The present disclosure relates to an organic electroluminescent compound, an organic electroluminescent material and an organic electroluminescent device comprising the same, a plurality of host materials comprising at least one first host material and at least one second host material, and an organic electroluminescent device comprising the same. By comprising the compound according to the present disclosure as a single host material or as a plurality of host materials, it is possible to produce an organic electroluminescent device having improved driving voltage, luminous efficiency, and/or lifetime properties compared to the conventional organic electroluminescent devices.

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 compound represented by the following general formula is excellent in light emission properties. R.sup.1 and R.sup.2 each independently represent a fluorinated alkyl group, D represents a substituent in which Hammett's σ.sub.p value is negative, and A represents a substituent in which Hammett's σ.sub.p value is positive. ##STR00001##

According to an aspect of the present disclosure, a compound having a metal planar tetradentate coordination configuration is disclosed. In the compounds, the metal M is Pt or Pd; the four coordinating atoms are Z.sup.1, Z.sup.2, Z.sup.3, and Z.sup.4 and are each selected from N, C, and O. The compound includes a substituent R, and atoms M, Z.sup.1, Z.sup.2, Z.sup.3, and Z.sup.4 are used to define a first plane that passes through the metal M and is positioned to have a minimum sum of shortest distances with Z.sup.1, Z.sup.2, Z.sup.3, and Z.sup.4. At least one non-hydrogen atom in R falls within a distal circle of a cylinder extending perpendicular to the first plane, where the distal circle of the cylinder is a height h from the base circle and the height h ranges from 3.3 Å to 4.8 Å.