An organic electroluminescent device having an anode, a cathode, and a light emitting layer between the anode and the cathode, in which the light emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following expression (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light emitting material, is capable of enhancing the light emission efficiency. E.sub.S1(A), E.sub.S1(B) and E.sub.S1(C) represent a lowest singlet excitation energy level of the first, second and third organic compound, respectively.
E.sub.S1(A)>E.sub.S1(B)>E.sub.S1(C)  (A)

Disclosed is an organic electroluminescent device, comprising a substrate and light emitting units formed in sequence on the substrate, characterized in that, each of the light emitting units comprises a first electrode layer (1), a light emitting layer (2) and a second electrode layer (3), the light emitting layer comprises a host material and a dye, the host material is made of materials having both electron transport capability and hole transport capability; at least one material in the host material has a CT excited triplet state energy level T.sub.1 greater than its n-π excited triplet state energy level S.sub.1, and T.sub.1-S.sub.1≤0.3 eV; or, at least one material in the host material has a CT excited triplet state energy level T.sub.1 greater than its n-π excited triplet state energy level S.sub.1, and T.sub.1-S.sub.1≥1 eV, with the difference between its n-π excited second triplet state energy level and its CT excited first singlet state energy level being in the range of −0.1 eV to 0.1 eV. The organic electroluminescent device configuration can sufficiently utilize the triplet state energy in the host material and the dye to increase the luminous efficiency and prolong the service life of the device.

A light emitting device having an anode, a cathode, a first organic layer and a second organic layer disposed between the anode and the cathode is provided. The first organic layer is a layer containing a light emitting material represented by the formula (T) and the second organic layer is a layer containing a crosslinked body of a polymer compound containing a crosslink constitutional unit wherein the variable groups are as defined in the specification: ##STR00001##

The present specification relates to a heterocyclic compound represented by Chemical Formula 1 and an organic light emitting device comprising the same.

Provided is an organic light emitting device including an anode; a cathode; and a light emitting layer provided between the anode and cathode, wherein an electron control layer provided between the light emitting layer and the cathode and including a compound of Chemical Formula 1: ##STR00001##
is included, and the light emitting layer includes a compound of Chemical Formula 3: ##STR00002##

It is an object of the present invention to provide an organic EL device in which, as a highly efficient and highly durable organic EL material, various materials excelling in electron injection/transport performance, hole blocking performance, hole resistance performance, exciton confinement performance, stability in a film state, and durability, are combined so that properties of each material can be effectively demonstrated, thereby achieving (1) high light emission efficiency and power efficiency, (2) low luminescence starting voltage, (3) low practical driving voltage, and (4) particularly long lifetime. An organic EL device including at least a anode, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and a cathode in this order, characterized in that the hole blocking layer includes a compound having a benzoazole structure represented by the following general formula (1). ##STR00001##
(In the formula, Ar.sup.1 and Ar.sup.2 may be the same or different from each other and each represent a hydrogen atom, a deuterium atom, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted fused polycyclic aromatic group, or a substituted or unsubstituted aromatic heterocyclic group. Y.sub.1 represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted fused polycyclic aromatic group, a substituted or unsubstituted aromatic heterocyclic group, a straight-chained or branched alkyl group that has 1 to 6 carbon atoms and may have a substituent group, a cycloalkyl group that has 5 to 10 carbon atoms and may have a substituent group, or a straight-chained or branched alkenyl group that has 2 to 6 carbon atoms and may have a substituent group. X represents an oxygen atom or a sulfur atom. Z.sub.1 and Z.sub.2 may be the same or different from each other and each represent a carbon atom or a nitrogen atom).

An organic electroluminescence device comprising: a cathode, an anode, and an organic layer disposed between the cathode and the anode, wherein the organic layer comprises a compound represented by the following formula (1), and a compound A having a Stokes shift of 20 nm or smaller and an emission peak wavelength of 440 nm to 465 nm (at least one of Ar.sub.1 and Ar.sub.2 is a monovalent group having a structure represented by the following formula (2)).

##STR00001##

A compound represented by the following formula (1), wherein in the formula, L.sub.1 and L.sub.2 are predetermined linking groups, and Ar.sub.1 is a monovalent group having a structure represented by the following formula (2).

##STR00001##

The present disclosure relates to compounds of Formula (1) as useful materials for OLEDs. A is CN, cyanoaryl, or heteroaryl having at least one nitrogen atom as a ring-constituting atom; and D.sup.1, D.sup.2 and D.sup.3 are diarylamino or carbazolyl. ##STR00001##

Embodiments of the present invention relate to an organic electronic device capable of ensuring high luminous efficiency, low driving voltage and high heat resistance, and improving color purity or lifespan.