Abstract: To provide an organic EL device having a low voltage, high efficiency and extended lifetime characteristics, and a host material for use in the organic EL device. A host material for an organic EL device, including a compound represented by the following general formula (1), or a structural isomer thereof: wherein X represents N or C—H and at least one thereof represents N, L independently represents an aromatic hydrocarbon group, and R2 to R6 represent hydrogen, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or a linked aromatic group in which two to five of these aromatic rings are linked to each other, provided that R2 and at least one of others do not represent hydrogen.

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. 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).