Abstract: To provide an organic electroluminescent device having long lifetime characteristics while having a low driving voltage and high power efficiency. The organic electroluminescent device includes 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 contains a host material including a first host material, a second host material and a third host material, and a light-emitting dopant material. A LUMO energy of the first host material is ?1.95 eV or less, and LM2?LM3?LM1 is satisfied under the assumption that LUMO energies of the first host material, the second host material and the third host material are LM1, LM2 and LM3, respectively.

Abstract: Provided is a blue light emitting organic EL device having high emission efficiency and a long lifetime. This organic EL device includes one or more light emitting layers between an anode and a cathode opposite to each other, wherein at least one of the light emitting layers has a difference between excited singlet energy (Si) and excited triplet energy (Ti) of 0.20 eV or less and includes a light emitting dopant represented by the following formula (5), a first host selected from biscarbazole compounds, and a second host selected from N-containing 6-membered ring compounds, wherein X3 is N—Ar4, O, or S and at least one X3 is N—Ar4.

Abstract: Provided is a blue light emitting organic EL device having high emission efficiency and a long lifetime. This organic EL device includes one or more light emitting layers between an anode and a cathode opposite to each other, wherein at least one of the light emitting layers includes a first host selected from indolocarbazole compounds, a second host selected from the compounds represented by the following general formula (2), and, as a light emitting dopant, a polycyclic aromatic compound represented by the following general formula (3) or a polycyclic aromatic compound represented by the general formula (3) as a substructure, wherein Y4 is B, P, P?O, P?S, Al, Ga, As, Si—R4 or Ge—R5, and X4 is O, N—Ar4, S or Se.

Abstract: Provided is a blue light emitting organic EL device having high emission efficiency and a long lifetime. This organic EL device comprises one or more light emitting layers between an anode and a cathode opposite to each other, wherein at least one of the light emitting layers contains a first host, a second host, and a light emitting dopant; the first host is a carbazole compound or a bicarbazole compound; the second host is an indolocarbazole compound; and the light emitting dopant is a polycyclic aromatic compound represented by the general formula (4) or a polycyclic aromatic compound having this structure as a partial structure. In the formula, Y4 is B, P, P?O, P?S, AL, Ga, As, Si—R4, or Ge—R41, and X4 is O, N—Ar4, S, or Se.

Abstract: Provided is a blue light emitting organic EL device having high emission efficiency and a long lifetime. This organic electroluminescent device includes one or more light emitting layers between an anode and a cathode opposite to each other, wherein at least one of the light emitting layers comprises one or more hosts selected from the indolocarbazole compounds represented by the following general formula (1) and, as a light emitting dopant, a polycyclic aromatic compound represented by the following general formula (2) or a polycyclic aromatic compound having the structure represented by the general formula (2) as a substructure, and wherein in the formulae Z is an indolocarbazole ring-containing group, X1 is O, N—Ar3, S, or Se, and Y1 is B, P, P?O, P?S, Al, Ga, As, Si—R2 or Ge—R3.

Abstract: An organic electroluminescent device having high efficiency and high driving stability, and a material suitable for the organic electroluminescent device are provided. The material for organic electroluminescent devices comprises an indolocarbazole compound represented by a general formula (1). In the formula, the ring a is represented by a formula (1a), X is NR, S, O or CR2, and Ar1 and Ar2 are an aromatic heterocyclic group represented by a formula (1b). Y is N or CR, and at least one is N. L1 is an aromatic hydrocarbon group. The material for the organic electroluminescent devices is suitable as material for the host of the light emitting layer or the hole blocking layer of organic EL devices.

Abstract: Provided is a blue light emitting organic EL device having high emission efficiency and a long lifetime. An organic electroluminescent device comprising one or more light emitting layers between an anode and a cathode opposite to each other, wherein at least one of the light emitting layers contains an organic emission material having a difference between excited singlet energy (S1) and excited triplet energy (T1) (?EST) of 0.20 eV or less as a light emitting dopant, a first host selected from the compounds represented by the following general formula (1), and a second host selected from the compounds represented by the following general formula (2).