Abstract: 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.

Abstract: An organic electroluminescence device includes an anode, an emitting layer, and a cathode, the emitting layer including a delayed-fluorescent first compound represented by a formula (1), and a fluorescent second compound. In the formula (1), Ar1 is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms and the like, and ArEWG is a substituted or unsubstituted heteroaryl group having 5 to 30 ring atoms and including one or more nitrogen atom in the ring, or an aryl group having 6 to 30 ring carbon atoms and substituted by one or more cyano group, at least one of Ar1 and ArX being at least one group selected from the group consisting of groups represented by a formula (1a) and the like.

Abstract: An organic electroluminescence device includes an anode, an emitting layer and a cathode, in which the emitting layer includes a first compound and a second compound, the first compound is a delayed fluorescent compound, the second compound is a fluorescent compound, an emission quantum efficiency of the first compound is 70% or less, and an ionization potential Ip1 of the first compound and an ionization potential Ip2 of the second compound satisfy a relationship of 0?Ip2?Ip1?0.8 eV.

Abstract: An organic electroluminescence device includes a pair of electrodes and an organic compound layer interposed therebetween. The organic compound layer includes a plurality of emitting layers at least including a first emitting layer and a second emitting layer. The first emitting layer contains a first host material and a fluorescent first luminescent material. The second emitting layer contains a second luminescent material that is different from the first luminescent material. A difference ?ST(H1) between singlet energy EgS(H1) of the first host material and an energy gap Eg77K(H1) at 77[K] of the first host material satisfies a specific relationship. One of the first luminescent material and the second luminescent material has a main peak wavelength from 400 nm to less than 500 nm and the other of the first luminescent material and the second luminescent material has a main peak wavelength from 500 nm to 700 nm.

Abstract: An organic electroluminescence device includes: an anode; a cathode; and an organic layer interposed between the anode and the cathode, in which the organic layer includes an emitting layer and the emitting layer includes a compound represented by a formula (1) below and a compound represented by a formula (2) below. Az1 of the formula (1) below and Az2 of the formula (2) below are each an azine ring. Cz of the formula (1) below and HAr of the formula (2) below are each a nitrogen-containing heterocyclic ring.

Abstract: An organic electroluminescence device including at least an anode, an emitting layer, an electron-transporting region and a cathode in sequential order, wherein the emitting layer contains a host and a dopant which gives fluorescent emission of which the main peak wavelength is 550 nm or less; the affinity Ad of the dopant is equal to or larger than the affinity Ah of the host; the triplet energy ETd of the dopant is larger than the triplet energy ETh of the host; and a blocking layer is provided within the electron-transporting region such that it is adjacent to the emitting layer, and the triplet energy ETb of the blocking layer is larger than ETh.

Abstract: An organic electroluminescence device includes an anode, a cathode, a first organic layer interposed between the anode and the cathode, a second organic layer interposed between the first organic layer and the cathode, and a bipolar layer interposed between the first organic layer and the second organic layer and having bipolar characteristics, in which at least one of the first organic layer and the second organic layer includes the first compound and the second compound, the first compound exhibits delayed fluorescence, and an energy gap T77K(M2) at 77[K] of the second compound is larger than an energy gap T77K(M1) at 77[K] of the first compound.

Abstract: An organic electroluminescence device includes: a cathode; an anode; and an organic thin-film layer having one or more layers and provided between the anode and the cathode, in which the organic layer includes an emitting layer. The emitting layer includes a first host material, a second host material and a phosphorescent dopant material. The first host material is a compound represented by a formula (1A). The second host material is a compound represented by a formula (2A).

Abstract: An organic EL device includes a pair of electrodes and an organic compound layer between pair of electrodes. The organic compound layer includes an emitting layer including a first material, a second material and a third material, in which singlet energy EgS(H) of the first material, singlet energy EgS(H2) of the second material, and singlet energy EgS(D) of the third material satisfy a specific relationship.

Abstract: An organic electroluminescence device includes a pair of electrodes and an organic compound layer interposed therebetween. The organic compound layer includes a plurality of emitting layers at least including a first emitting layer and a second emitting layer. The first emitting layer contains a first host material and a fluorescent first luminescent material. The second emitting layer contains a second luminescent material that is different from the first luminescent material. A difference ?ST(H1) between singlet energy EgS(H1) of the first host material and an energy gap Eg77K(H1) at 77[K] of the first host material satisfies a specific relationship. One of the first luminescent material and the second luminescent material has a main peak wavelength from 400 nm to less than 500 nm and the other of the first luminescent material and the second luminescent material has a main peak wavelength from 500 nm to 700 nm.

Abstract: An organic EL device includes a pair of electrodes and an organic compound layer between pair of electrodes. The organic compound layer includes an emitting layer including a first material and a second material. The second material is a fluorescent material. Singlet energy EgS(H) of the first material and singlet energy EgS(D) of the second material satisfy a relationship of the following formula (1). The first material satisfies a relationship of the following formula (2) in terms of a difference ?ST(H) between the singlet energy EgS(H) and an energy gap Eg77K(H) at 77K. EgS(H)>EgS(D)??(1) ?ST(H)=EgS(H)?Eg77K(H)<0.

Abstract: An organic electroluminescence device includes a pair of electrodes and an organic compound layer interposed therebetween. The organic compound layer includes a plurality of emitting layers at least including a first emitting layer and a second emitting layer. The first emitting layer contains a first host material and a fluorescent first luminescent material. The second emitting layer contains a second luminescent material that is different from the first luminescent material. A difference ?ST(H1) between singlet energy EgS(H1) of the first host material and an energy gap Eg77K(H1) at 77[K] of the first host material satisfies a specific relationship. One of the first luminescent material and the second luminescent material has a main peak wavelength from 400 nm to less than 500 nm and the other of the first luminescent material and the second luminescent material has a main peak wavelength from 500 nm to 700 nm.

Abstract: An organic EL device includes a pair of electrodes and an organic compound layer between pair of electrodes. The organic compound layer includes an emitting layer including a first material, a second material and a third material, in which singlet energy EgS(H) of the first material, singlet energy EgS(H2) of the second material, and singlet energy EgS(D) of the third material satisfy a specific relationship.

Abstract: 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.

Abstract: An organic electroluminescence device includes an anode, an emitting layer and a cathode, in which the emitting layer includes a first compound, a second compound and a third compound. The first compound is a delayed fluorescent compound. The first compound has an energy gap T77K at 77 [K] larger than an energy gap T77K at 77 [K] of the second compound. The third compound has an energy gap T77K at 77 [K] larger than the energy gap T77K at 77 [K] of the second compound. The second compound has a fused ring structure represented by a formula (2) below and has eight or less rings in total.

Abstract: An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material and a second material represented by a formula (21) below. The first material has a singlet energy larger than a singlet energy of the second material.

Abstract: An organic electroluminescence device includes an anode, an emitting layer and a cathode, in which the emitting layer includes a first compound and a second compound. The first compound is a compound represented by a formula (1) below and the second compound is a fluorescent compound.

Abstract: An organic electroluminescence device includes: an anode; a cathode; and an organic layer interposed between the anode and the cathode, in which the organic layer includes an emitting layer and the emitting layer includes a compound represented by a formula (1) below and a compound represented by a formula (2) below. Az1 of the formula (1) below and Az2 of the formula (2) below are each an azine ring. Cz of the formula (1) below and HAr of the formula (2) below are each a nitrogen-containing heterocyclic ring.

Abstract: An organic electroluminescence device includes: an anode; a cathode; and a single- or multi-layer organic layer interposed between the anode and the cathode. The organic layer includes at least one emitting layer containing a dopant material represented by a formula below. In the formula, X1 to X5 each independently represent CR1 or a nitrogen atom, at least one of X1 to X5 is a nitrogen atom, L1 represents a divalent aromatic hydrocarbon group or a divalent heterocyclic group, A and B each independently represents a cyclic structure, at least one of the cyclic structure A and the cyclic structure B has a substituent, and R1 represents an aryl group, alkyl group or the like.

Abstract: An organic electroluminescence device includes an anode, an emitting layer and a cathode, in which the emitting layer includes a first compound and a second compound. The first compound is a delayed-fluorescent compound. The second compound is represented by a formula (2) below, in which X is a nitrogen atom or a carbon atom bonded to Y; R21 to R26 are each independently a hydrogen atom or a substituent; Z21 and Z22 are each independently selected from the group consisting of a halogen atom, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, and a substituted or unsubstituted aryloxy group.