Abstract: An emitting layer of an organic EL device contains a fluorescent first compound, a delayed fluorescent second compound, and a third compound that satisfy numerical formulae (Numerical Formula 1) to (Numerical Formula 4). (Numerical Formula 1): |Af(M1)?Af(M2)|?0.40 eV, (Numerical Formula 2): Ip(M2)?5.75 eV, (Numerical Formula 3): |Ip(M2)?Ip(M3)|?0.25 eV, (Numerical Formula 4): S1(M3)?S1(M2). Af(M1) is an affinity of the first compound, Af(M2) is an affinity of the second compound, Ip(M2) is an ionization potential of the second compound, S1(M2) is a lowest singlet energy of the second compound, Ip(M3) is an ionization potential of the third compound, and S1(M3) is a lowest singlet energy of the third compound.

Abstract: An organic electroluminescence device includes an emitting layer between an anode and a cathode, and a first layer between the anode and the emitting layer, in which the emitting layer contains a delayed fluorescent compound M1 represented by a formula (1), the first layer contains a compound M4 represented by a formula (4), and the compound M4 satisfies formulae (a) and (b), ?H(M4)?1.0×10?3 cm2/Vs??Formula (a): S1(M4)?3.15 eV??Formula (b): where: ?H(M4) represents hole mobility of the compound M4; and S1(M4) represents a lowest singlet energy of the compound M4.

Abstract: An organic electroluminescence device includes an anode, a cathode, and an emitting layer provided between the anode and the cathode, in which the emitting layer contains a delayed fluorescent compound M2 represented by a formula (2) and a compound M3 represented by a formula (3), and a singlet energy Si(M2) of the compound M2 and a singlet energy Si(M3) of the compound M3 satisfy a relationship of a numerical formula (Numerical Formula 1).

Abstract: An organic electroluminescence device includes a cathode, an anode, a charge generating layer provided between the cathode and the anode, a first emitting unit provided between the charge generating layer and the cathode, and a second emitting unit provided between the charge generating layer and the anode. The first emitting unit includes a blue emitting layer containing a first compound represented by a formula and a second compound emitting a blue light, in which Z1 is represented by a formula and a cyclic structure represented by a formula or is fused to Z1, and X1 and X2 are each an oxygen atom or a sulfur atom.

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 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 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 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 that includes an anode, an emitting layer that includes a host and a fluorescent dopant, an electron transporting zone, a cathode, a blocking layer adjacent to the emitting layer in the electron transporting zone where the blocking layer includes an aromatic heterocyclic derivative with an azine ring and where the triplet energy ETb (eV) of the aromatic heterocyclic derivative is larger than a triplet energy ETh (eV) of the host.

Abstract: An organic electroluminescence device that includes an anode, an emitting layer that includes a host and a fluorescent dopant, an electron transporting zone, a cathode, a blocking layer adjacent to the emitting layer in the electron transporting zone where the blocking layer includes an aromatic heterocyclic derivative with an azine ring and where the triplet energy ETb (eV) of the aromatic heterocyclic derivative is larger than a triplet energy ETh (eV) of the host.

Abstract: An organic electroluminescence device including: an anode (10), a cathode (70), an emitting layer (40) including an organic compound, which is between the anode (10) and the cathode (70), two or more layers arranged in a hole injection and transport region which is between the anode (10) and the emitting layer (40), and one or more layers arranged in an electron injection and transport region which is between the emitting layer (40) and the cathode (70), wherein a layer in the hole injection and transport region, which is in contact with the emitting layer (40), includes an aromatic amine derivative having a carbazole skeleton, one of the layers other than the layer in contact with the emitting layer (40) in the hole injection and transport region includes one or more materials selected from the group consisting of thiophene derivatives, tricyclic or more cyclic fused aromatic derivatives, amine derivatives excluding the compound represented by the following formula (A), conductive polymers, CFx, CuPc, transi

Abstract: An organic electroluminescence device including an anode, an emitting layer, a blocking layer, an electron-injecting layer 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 smaller than the affinity Ah of the host; the triplet energy ETd of the dopant is larger than the triplet energy ETh of the host; the triplet energy ETb of the blocking layer is larger than ETh; and the blocking layer includes an aromatic hydrocarbon compound.

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 that includes an anode, an emitting layer that includes a host and a dopant, a blocking layer, an electron injecting layer, and a cathode where the blocking layer includes an aromatic heterocyclic derivative, the triplet energy ETb (eV) of the blocking layer is larger than a triplet energy ETh (eV) of the host, and the affinity Ab (eV) of the blocking layer and an affinity Ae (eV) of the electron injecting layer satisfy a relationship of Ae?Ab<0.2.

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 including a first emitting layer and a second emitting layer, in which at least one of the first and second emitting layers contains a phosphorescent dopant material, and a space layer between the first and second emitting layers. The space layer contains a compound satisfying a relationship of the following numerical formula (1) in terms of a difference ?ST between singlet energy EgS and an energy gap Eg77K at 77K, [Numerical Formula 1] ?ST=EgS?Eg77K?0.5 (eV)??(1).

Abstract: An organic electroluminescence device includes an anode, a cathode and layers between the anode and the cathode, the layers at least including a hole transporting layer, a first emitting layer, a second emitting layer and an electron transporting layer, in which the first emitting layer includes a first host material and a first luminescent material and the second emitting layer is continuously formed on the first emitting layer near the cathode and includes a second host material and a second luminescent material. The second host material is a monoazine derivative, a diazine derivative, or a triazine derivative. The first and second luminescent materials are different metal complexes.

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 including a first emitting layer and a second emitting layer, in which at least one of the first and second emitting layers contains a phosphorescent dopant material, and a space layer between the first and second emitting layers. The space layer contains a compound satisfying a relationship of the following numerical formula (1) in terms of a difference ?ST between singlet energy EgS and an energy gap Eg77K at 77K, [Numerical Formula 1] ?ST=EgS?Eg77K?0.5 (eV)??(1).

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: A tandem organic electroluminescence device including a first emitting unit (3), an intermediate unit (4) and a second emitting unit (5) being stacked between opposing electrodes (2) and (6) the first emitting unit (3) including a blue fluorescent dopant and a red fluorescent dopant and the second emitting unit (5) including a red phosphorescent dopant and a green phosphorescent dopant.

Abstract: An organic EL device includes: an anode for injecting holes; a phosphorescent-emitting layer; a fluorescent-emitting layer; and a cathode for injecting electrons. The phosphorescent-emitting layer contains a phosphorescent host and a phosphorescent dopant for phosphorescent emission. The fluorescent-emitting layer contains a fluorescent host and a fluorescent dopant for fluorescent emission. The fluorescent host is at least one of an asymmetric anthracene derivative represented by a formula (1) below and a pyrene derivative represented by a formula (2) below.