Organic element for electroluminescent devices
View Patent ↗Disclosed is an OLED device comprising a light-emitting layer (LEL) containing a host and an emitting dopant located between a cathode and an anode wherein the dopant is a naphthacene derivative represented by formula (I): wherein: a) said naphthacene derivative contains at least one fluorine or fluorine containing group; and b) when exactly two fluorine containing groups are present said groups are not located at the 5- and 12-positions or at the 6- and 11-positions.
1. An OLED device comprising a light-emitting layer (LEL) containing a host and an emitting dopant located between a cathode and an anode wherein the dopant is a naphthacene derivative represented by formula (II):
wherein:
R 5 , R 6 , R 11 and R 12 are phenyl groups;
at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 and R 12 is or contains a fluorine or a fluorine containing group:
provided that the remaining R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 and R 12 are selected from hydrogen and substituent groups; and
provided further that when exactly two fluorine containing groups are present said groups are not located at R 5 and R 12 or at R 6 and R 11 , and further provided that the substituents are selected so that naphthacene derivative has a wavelength of maximum emission (λ max ) in ethyl acetate solution such that 520 nm≦λ max ≦650 nm.
2. The device of claim 1 comprising a further light-emitting compound to provide a white light emission.
3. The device of claim 2 further comprising a blue light-emitting compound to provide a white light emission.
4. The device of claim 2 further comprising a filter over-lying the device.
5. The device of claim 2 wherein the layer comprises a host and emitting dopant where the dopant is present in an amount of up to 10%-wt of the host.
6. The device of claim 5 wherein the emitting dopant is present in an amount of 0.1–5.0%-wt of the host.
7. The device of claim 1 wherein the emitting dopant is represented by formula (III):
wherein:
W, X, Y and Z are independently 0–5;
R 13 , R 14 , R 15 , and R 16 are selected from hydrogen and substituent groups; and
provided further that when exactly two fluorine or fluorine containing groups are present said groups are not located at R 14 and R 15 or at R 13 and R 16 .
8. The device of claim 7 wherein the emitting dopant is represented by formula (IV):
wherein:
W, X, Y and Z are independently 0–5;
at least one of R 2 , R 3 , R 8 , R 9 , R 13 , R 14 , R 15 , and R 16 is fluorine or a fluorine containing group:
provided that the remaining R 2 , R 3 , R 8 , R 9 , R 13 , R 14 , R 15 , and R 16 are selected from hydrogen and substituent groups;
provided further that when exactly two fluorine or fluorine containing groups are present said groups are not located at R 14 and R 15 or at R 13 and R 16 .
9. The device of claim 8 wherein the emitting dopant is represented by formula (V):
wherein:
W, X, Y and Z are independently 0–5;
at least one of R 13 , R 14 , R 15 , and R 16 is fluorine or a fluorine containing group;
provided that the remaining R 13 , R 14 , R 15 , and R 16 are selected from hydrogen and substituent groups;
provided further that when exactly two fluorine or fluorine containing groups are present said groups are not located at R 14 and R 15 or at R 13 and R 16 .
10. The device of claim 7 wherein the layer comprises a host and dopant where the dopant is present in an amount of up to 10%-wt of the host.
11. The device of claim 10 wherein the dopant is present in an amount of 0.1–5.0%-wt of the host.
12. The device of claim 7 comprising a further compound to provide a white light emission.
13. The device of claim 12 further comprising a blue light-emitting compound to provide a white light emission.
14. The device of claim 12 further comprising a filter over-lying the device.
15. A light-emitting display containing the OLED device of claim 7 .
16. The device of claim 1 wherein the emitting dopant is represented by formula (VI):
wherein:
R 18 , is fluorine or a fluorine containing group:
R 17 is a substituent;
m is 0–5.
17. The device of claim 16 wherein R 17 and R 18 are selected from alkyl, alkoxy, acetylenic, alkenyl, cyano, carbocylic, fluoro, heterocyclic, trifluoromethyl, pentafluoroethyl and fluorinated-phenyl groups and at least one of R 17 and R 18 is fluorine or a fluorine containing group.
18. The device of claim 17 wherein R 17 and R 18 are selected from alkyl, alkoxy, carbocylic, fluoro, trifluoromethyl, pentafluoroethyl and fluorinated-phenyl groups and at least one of R 17 and R 18 is fluorine or a fluorine containing group.
19. The device of claim 17 wherein R 17 and R 18 are selected from tert-butyl, methoxy, phenyl, fluoro, trifluoromethyl, pentafluoroethyl and fluorinated-phenyl groups and at least one of R 17 and R 18 is fluorine or a fluorine containing group.
20. The device of claim 1 wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 and R 12 is selected from alkyl, aromatic carbocyclic and aromatic heterocyclic groups containing fluorine or fluorine containing groups.
21. The device of claim 20 wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 and R 12 is an aromatic carbocyclic group containing fluorine or fluorine containing groups.
22. The device of claim 1 wherein the host is an amine compound.
23. The device of claim 1 wherein the host comprises N,N′-di-1-naphthalenyl-N,N′-diphenyl-4,4′-diaminobiphenyl.
24. The device of claim 1 wherein the substituents are selected to provide an emitted light having an orange-red hue.
25. The device of claim 1 wherein the substituents are selected to provide a reduced loss of initial luminance compared to the device containing no naphthacene compound.
26. The device of claim 1 wherein the naphthacene compound is selected from the following:
27. An OLED device of claim 1 wherein the naphthacene derivative has a wavelength of maximum emission (λ max ) in ethyl acetate solution such that 530 nm≦λ max ≦625 nm.
28. A light emitting device containing the OLED device of claim 1 .
29. A method of emitting light comprising subjecting the device of claim 1 to an applied voltage.
30. The device of claim 1 wherein: either
a) the sublimation temperature of said naphthacene derivative is lower by at least 5° C. than the derivative without fluorine or fluorine containing groups; or
b) the naphthacene derivative sublimes and the derivative without the fluorine or fluorine containing groups melts.
31. An OLED device of claim 30 wherein the naphthacene derivative has a sublimation temperature of at least 10° C. lower than that of the naphthacene without fluorine or fluorine containing groups.
32. An OLED device of claim 31 wherein the naphthacene derivative has a sublimation temperature of at least 15° C. lower than that of the naphthacene without fluorine or fluorine containing groups.
33. An OLED device of claim 31 wherein the naphthacene derivative has a sublimation temperature of at least 20° C. lower than that of the naphthacene without fluorine or fluorine containing groups.