Light-emitting element using spirofluorene derivative and electronic appliance
View Patent ↗It is an object to provide a light-emitting element with high luminous efficiency by using a hole transporting substance with a sufficiently high T 1 level. Further, it is another object to provide a light-emitting device and an electronic appliance with low power consumption by using a hole transporting substance with a sufficiently high T 1 level. The present invention provides a light-emitting element which has a first layer containing a spiro-9,9′-bifluorene derivative in which one amino group is combined and a second layer containing a phosphorescent compound between an anode and a cathode.
1. A light-emitting element comprising:
a first layer over an anode;
an N layer over the first layer;
a P layer over the N layer;
a second layer over the P layer; and
a cathode over the second layer,
wherein each of the first layer and the second layer contains a third layer and a fourth layer over the third layer,
wherein the third layer contains a spirofluorene derivative represented by the structure:
wherein R 1 is any one of hydrogen and an alkyl group having 1 to 4 carbon atoms, each of R 2 and R 3 is any one of hydrogen and an alkyl group having 1 to 4 carbon atoms and R 2 and R 3 may be identical or different, R 4 is an aryl group having 6 to 15 carbon atoms, each of R 5 and R 6 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 15 carbon atoms and R 5 and R 6 may be identical or different,
wherein the fourth layer contains a phosphorescent compound,
wherein the N layer contains an organic compound and an electron donor, and
wherein the P layer contains an organic compound and an electron acceptor.
2. A light-emitting element according to claim 1 , wherein R 4 is a substituent represented by the structure:
wherein R 19 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 15 carbon atoms.
3. A light-emitting element according to claim 1 , wherein R 4 is a phenyl group and each of R 5 and R 6 is hydrogen.
4. A light-emitting element according to claim 1 , wherein R 4 is a phenyl group and each of R 1 , R 5 and R 6 is hydrogen.
5. A light-emitting element according to claim 1 , wherein R 4 is a phenyl group and each of R 1 , R 2 , R 3 , R 5 and R 6 is hydrogen.
6. A light-emitting element comprising:
a first layer over an anode;
an N layer over the first layer;
a P layer over the N layer;
a second layer over the P layer; and
a cathode over the second layer,
wherein each of the first layer and the second layer contains a third layer and a fourth layer over the third layer,
wherein the third layer contains a spirofluorene derivative represented by the structure:
wherein R 7 is any one of hydrogen and an alkyl group having 1 to 4 carbon atoms, each of R 8 and R 9 is any one of hydrogen and an alkyl group having 1 to 4 carbon atoms and R 8 and R 9 may be identical or different, R 10 is an aryl group having 6 to 15 carbon atoms, each of R 11 and R 12 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 15 carbon atoms and R 11 and R 12 may be identical or different,
wherein the fourth layer contains a phosphorescent compound,
wherein the N layer contains an organic compound and an electron donor, and
wherein the P layer contains an organic compound and an electron acceptor.
7. A light-emitting element according to claim 6 , wherein R 10 is a substituent represented by the structure:
wherein R 20 any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 15 carbon atoms.
8. A light-emitting element according to claim 6 , wherein R 10 is a phenyl group and each of R 11 and R 12 is hydrogen.
9. A light-emitting element according to claim 6 , wherein R 10 is a phenyl group and each of R 7 , R 11 and R 12 is hydrogen.
10. A light-emitting element according to claim 6 , wherein R 10 is a phenyl group and each of R 7 , R 8 , R 9 , R 11 and R 12 is hydrogen.
11. A light-emitting element comprising:
a first layer over an anode;
an N layer over the first layer;
a P layer over the N layer;
a second layer over the P layer; and
a cathode over the second layer,
wherein each of the first layer and the second layer contains a third layer and a fourth layer over the third layer,
wherein the third layer contains a spirofluorene derivative represented by the structure:
wherein R 13 is any one of hydrogen and an alkyl group having 1 to 4 carbon atoms, each of R 14 and R 15 is any one of hydrogen and an alkyl group having 1 to 4 carbon atoms and R 14 and R 15 may be identical or different, R 16 is an aryl group having 6 to 15 carbon atoms, R 17 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 15 carbon atoms, and R 18 is any one of an alkyl group having 1 to 4 carbon atoms and an aryl group having 6 to 15 carbon atoms,
wherein the fourth layer contains a phosphorescent compound,
wherein the N layer contains an organic compound and an electron donor, and
wherein the P layer contains an organic compound and an electron acceptor.
12. A light-emitting element according to claim 11 , wherein R 16 and R 18 each are a substituent represented by the structure:
wherein R 21 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 15 carbon atoms.
13. A light-emitting element according to claim 11 , wherein each of R 16 and R 18 is a phenyl group and R 17 is hydrogen.
14. A light-emitting element according to claim 11 , wherein each of R 16 and R 18 is a phenyl group and each of R 13 and R 17 is hydrogen.
15. A light-emitting element according to claim 11 , wherein each of R 16 and R 18 is a phenyl group and each of R 13 , R 14 , R 15 and R 17 is hydrogen.
16. The light-emitting element according to any one of claims 1 to 11 ,
wherein the electron donor is selected from an alkali metal and an alkaline-earth metal.
17. The light-emitting element according to any one of claims 1 to 11 ,
wherein the electron acceptor is a transition metal oxide.
18. An electronic appliance comprising:
a display portion using the light-emitting element according to any one of claims 1 to 11 .
19. A lighting device comprising the light-emitting element according to any one of claims 1 to 11 .