Organic electroluminescent element
View Patent ↗Provided is an organic electroluminescent device (organic EL device) that is improved in luminous efficiency, sufficiently secures driving stability, and has a simple construction. The organic electroluminescent device includes an organic layer including a light-emitting layer between an anode and cathode laminated on a substrate, and at least one layer of the organic layer contains a carbazole compound represented by the following formula (1). It is advantageous to incorporate the carbazole compound as a host material into the light-emitting layer. In the formula (1), A represents a direct bond or an n-valent group, E represents oxygen or sulfur, and n represents an integer of 2 to 4.
1. An organic electroluminescent device, comprising:
a substrate;
an anode;
an organic layer; and
a cathode,
the anode, the organic layer, and the cathode being laminated on the substrate,
wherein the organic layer comprises at least one layer selected from the group consisting of a light-emitting layer, a hole-transporting layer, an electron-transporting layer, and a hole-blocking layer, the at least one layer containing a carbazole compound represented by the general formula (1):
where:
A represents an n-valent aromatic hydrocarbon group having 6 to 18 carbon atoms, an n-valent aromatic heterocyclic group having 3 to 17 carbon atoms, or an n-valent group obtained by linking 2 to 4 aromatic rings each selected from an aromatic hydrocarbon ring having 6 to 18 carbon atoms and an aromatic heterocyclic ring having 3 to 17 carbon atoms, and the aromatic hydrocarbon group, the aromatic heterocyclic group, the aromatic hydrocarbon ring, and the aromatic heterocyclic ring may each have a substituent;
R's represents hydrogen;
E represents oxygen or sulfur; and
n represents an integer of 2 to 4.
2. An organic electroluminescent device according to claim 1 , wherein A in the general formula (1) represents any one of an n-valent aromatic heterocyclic group having 3 to 17 carbon atoms, and an n-valent group obtained by linking 2 to 4 aromatic rings, each of which is an aromatic heterocyclic ring having 3 to 17 carbon atoms.
3. An organic electroluminescent device according to claim 2 , wherein A represents any one of the n-valent aromatic heterocyclic group, and the n-valent group obtained by linking 2 to 4 aromatic rings, each of which is an aromatic heterocyclic ring having 3 to 17 carbon atoms, and n represents 2 or 3.
4. An organic electroluminescent device according to claim 1 , wherein the layer containing the carbazole compound represented by the general formula (1) comprises a light-emitting layer containing a phosphorescent light-emitting dopant.
5. An organic electroluminescent device according to claim 1 , wherein the carbazole compound is selected from: