| 摘要 |
Provided is an organic electroluminescent device (organic EL device), which has improved luminous efficiency, shows sufficiently ensured driving stability, and has a simple construction. The organic electroluminescent device includes an anode, a cathode, and organic layers including a hole-transporting layer and a light-emitting layer, the organic layers being interposed between the anode and the cathode, in which the light-emitting layer contains a phosphorescent light-emitting material and the hole-transporting layer and the light-emitting layer have an electron- and/or exciton-blocking layer therebetween, the electron- and/or exciton-blocking layer being adjacent to the light-emitting layer and containing an indolocarbazole compound represented by the general formula (2). In the formula, a ring B represents a heterocycle represented by the formula (1c) to be fused with adjacent rings, Z represents an n-valent aromatic hydrocarbon group or an aromatic heterocyclic group, and n represents 1 or 2. |
| 主权项 |
1. An organic electroluminescent device, comprising:
an anode; a cathode; and organic layers comprising at least: a hole-injecting layer; a hole-transporting layer; a single light-emitting layer, and an electron-transporting layer, the organic layers being interposed between the anode and the cathode, wherein: the single light-emitting layer comprises a phosphorescent light-emitting material and a host material; the hole-transporting layer consists essentially of one or more compounds selected from the group consisting of a triazole derivative, an oxadiazole derivative, an imidazole derivative, a carbazole derivative, a polyarylalkane derivative, a pyrazoline derivative, a pyrazolone derivative, a phenylenediamine derivative, an arylamine derivative, an amino-substituted chalcone derivative, an oxazole derivative, a styrylanthracene derivative, a fluorenone derivative, a hydrazone derivative, a stilbene derivative, a silazane derivative, an aniline-based copolymer, and a thiophene oligomer; and the hole-transporting layer and the single light-emitting layer have an electron- and/or exciton-blocking layer therebetween, the electron- and/or exciton-blocking layer being adjacent to the single light-emitting layer and containing an indolocarbazole compound represented by the following general formula (1): in the general formula (1): Z represents an n-valent aromatic hydrocarbon group having a total of 6 to 50 carbon atoms or an aromatic heterocyclic group having a total of 3 to 50 carbon atoms; Y represents a group represented by the formula (1a); n represents an integer of 2 to 6; and Y's may be identical to or different from each other; in the formula (1a): a ring A represents an aromatic ring represented by the formula (1b) to be fused with adjacent rings; a ring B represents a heterocycle represented by the formula (1c) to be fused with adjacent rings; and R1 and R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having a total of 1 to 10 carbon atoms, an aromatic hydrocarbon group having a total of 6 to 12 carbon atoms, or an aromatic heterocyclic group having a total of 3 to 11 carbon atoms; in the formula (1 b): X represents a methine group or a nitrogen atom; R3 represents a hydrogen atom, an aliphatic hydrocarbon group having a total of 1 to 10 carbon atoms, an aromatic hydrocarbon group having a total of 6 to 12 carbon atoms, or an aromatic heterocyclic group having a total of 3 to 11 carbon atoms, provided that R3 may be fused with a ring including X to form a fused ring; and in the formula (1c), Ar represents an aromatic hydrocarbon group having a total of 6 to 50 carbon atoms or an aromatic heterocyclic group having a total of 3 to 50 carbon atoms; wherein: the indolocarbazole compound contained in the electron- and/or exciton-blocking layer has a LUMO energy higher than a LUMO energy of the host material contained in the single light-emitting layer and has a LUMO energy in eV of greater than or equal to −1.2, the hole-transporting material contained in the hole-transporting layer has a HOMO energy higher than a HOMO energy of the indolocarbazole compound contained in the electron- and/or exciton-blocking layer and has a HOMO energy in eV of greater than or equal to −4.8. |
