Organic element for electroluminescent devices
View Patent ↗An electroluminescent device comprising a host material and a rubrene derivative having a naphthacene nucleus comprising four fused phenyl rings a, b, c, and d, in order, containing two secondary phenyl ring groups linked to the “c” ring, each bearing directly or indirectly a fluoro or perfluoroalkyl group, wherein each fluoro or perfluoroalkyl group is either: a) linked directly to one of said secondary phenyl rings and is located on a meta or ortho position, or b) located in any position of another aryl group linked directly or indirectly to one of the secondary phenyl rings.
1. An electroluminescent device comprising a host material and a rubrene derivative having a naphthacene nucleus comprising four fused phenyl rings a, b, c, and d, in order, wherein the rubrene derivative is represented by Formula (1),
wherein:
Ar 1 , Ar 2 , and Ar 3 represent independently selected aryl groups;
each G represents an independently selected substituent;
each m is independently 0–4;
V 1 –V 5 represent hydrogen or independently selected substituent groups, provided there are in total two fluoro or perfluoroalkyl groups linked directly or indirectly to the “c” ring, selected from those where:
a) at least one of V 1 –V 4 represents a fluoro or perfluoroalkyl group,
or
b) at least one of V 1 –V 5 and Ar 3 includes an aryl ring bearing a fluoro or trifluoroalkyl group.
2. The device of claim 1 wherein the perfluoroalkyl group is a trifluoromethyl group.
3. The device of claim 1 wherein the secondary phenyl ring on the “c” ring bears a fluoro or perfluoromethyl group on a meta- or ortho-position of that ring.
4. The device of claim 1 wherein the each secondary phenyl ring on the “c” ring bears a fluoro or trifluoromethyl group on a meta- or ortho-position.
5. The device of claim 1 wherein at least one secondary phenyl ring on the “c” ring bears a meta- or ortho-fluoro substituent.
6. The device of claim 1 at least one secondary phenyl ring on the “c” ring is linked to an aryl group that is substituted with a fluoro or perfluoroalkyl group.
7. The device of claim 6 wherein the aryl group is a phenyl group that bears a meta- or para-fluoro substituent.
8. The device of claim 1 , wherein the rubrene derivative is represented by Formula (1),
wherein:
Ar 1 , Ar 2 , and Ar 3 represent independently selected aryl groups;
each G represents an independently selected substituent;
each m is independently 0–4;
V 1 –V 5 represent hydrogen or independently selected substituent groups, provided there are in total two fluoro or perfluoroalkyl groups linked directly or indirectly to the “c” ring, selected from those where:
a) at least one of V 1 –V 4 represents a fluoro or perfluoroalkyl group,
or
at least one of V 1 –V 5 and Ar 3 includes an aryl ring bearing a fluoro or trifluoromethyl group.
9. The device of claim 1 , wherein V 3 represents a fluoro substituent.
10. The device of claim 9 , wherein at least one of V 2 , V 3 or V 5 includes a phenyl ring bearing a fluoro or perfluoroalkyl group.
11. The device of claim 9 wherein the substituents are selected to provide an emitted light having an orange-red hue.
12. The device of claim 9 wherein the substituents are selected to provide an emitted light having a wavelength of maximum emission (λ max ) in ethyl acetate solution such that
520 nm≦λ max ≦650 nm.
13. The device of claim 9 wherein the substituents are selected to provide a reduced loss of initial luminance compared to the device containing no rubrene derivative.
14. The device of claim 1 wherein:
either
a) the sublimation temperature of said derivative is lower by at least 5° C. than the derivative without the fluoro or perfluoroalkyl groups;
or
b) the derivative sublimes and the derivative without the fluoro or perfluoroalkyl groups melts.
15. A device of claim 1 wherein the derivative has a sublimation temperature of at least 10° C. lower than that of the rubrene without fluorine or fluorine containing groups.
16. The device of claim 1 , further comprising a blue or blue-green light-emitting compound to provide a white light emission.
17. The device of claim 16 wherein the blue or blue-green light-emitting material comprises a perylene group.
18. The device of claim 16 wherein the blue or blue-green light-emitting material comprises a material of one of the following structures:
wherein:
R a –R h independently represent hydrogen or one or more an independently selected substituents.
19. The device of claim 18 wherein the blue or blue-green light-emitting material comprises 1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]benzene (BDTAPVB) or 1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]biphenyl.
20. The device of claim 16 , wherein, the blue or blue-green light-emitting compound comprises a boron complex.
21. The device of claim 20 wherein the blue or blue-green light-emitting material comprises a compound represented the following structure:
wherein:
Ar a and Ar b independently represent the atoms necessary to form an aromatic ring group;
w represents N or C—Y, wherein Y represents hydrogen or a substituent; and
Z a and Z b represent independently selected substituents.
22. The device of claim 21 wherein w represents N.
23. The device of claim 1 , further comprising a red light-emitting compound to provide a white light emission.
24. The device of claim 23 wherein the red light-emitting compound comprises a diindenoperylene compound of the following structure:
wherein:
R 1 –R 16 are independently selected as hydrogen or a substituent.
25. The device of claim 24 , wherein R 1 , R 4 , R 9 , R 12 represent independently selected phenyl groups, R 2 , and R 3 as well as R 10 and R 11 form independently selected fused benzene ring groups.
26. The device of claim 1 , wherein the host material is a hole-transporting material.
27. The device of claim 1 , wherein the host material is a hole-transporting material comprising a tertiary amine.
28. The device of claim 1 , wherein the host material is an electron-transporting material.
29. The device of claim 28 , wherein the electron-transporting material comprises a metal complex of 8-hydroxyquinoline.
30. The device of claim 1 wherein the derivative is present in an amount of up to 10%-wt of the host material.
31. The device of claim 1 wherein the derivative is present in an amount of up to 0.1–5.0%-wt of the host material.
32. A display comprising the electroluminescent device of claim 1 .
33. The device of claim 1 wherein white light is produced either directly or by using filters.
34. An area lighting device comprising the electroluminescent device of claim 1 .
35. A process for emitting light comprising applying a potential across the device of claim 1 .