An Organic Electronic Device Comprising an Anode Layer, a Cathode Layer, at Least One Emission Layer (EML) and at Least One Hole Injection Layer (HIL)

Abstract

The present invention relates to an organic electronic device comprising an anode layer, a cathode layer, at least one emission layer (EML) and at least one hole injection layer (HIL), wherein the hole injection layer is arranged between the anode layer and the at least one emission layer.

Claims

1. An organic electronic device comprising an anode layer, a cathode layer, at least one emission layer (EML) and at least one hole injection layer (HIL), wherein the hole injection layer is arranged between the anode layer and the at least one emission layer; wherein the hole injection layer comprises an organic matrix compound (OMC) and a metal complex, wherein the metal complex has the formula (II):
M.sup.n⊕(L.sup.θ).sup.n   (II), wherein M is a metal ion, n is the valency of M, wherein n is an integer from 1 to 4 L is a ligand; and the at least one emission layer comprises at least one emitter matrix compound (EMC), wherein the HOMO level of the emitter matrix compound (EMC) and the HOMO level of the organic matrix compound (OMC) fulfills the following equation:
−0.24 eV <[HOMO level (EMC)−HOMO level (OMC)]≤0.8 eV.

2. An organic electronic device comprising an anode layer, a cathode layer, at least one emission layer (EML) and at least one hole injection layer (HIL), wherein the hole injection layer is arranged between the anode layer and the at least one emission layer, wherein the hole injection layer comprises an organic matrix compound (OMC) and a metal complex, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) have the formula (I):
(Ar.sup.1).sub.k—(Ar.sup.2).sub.m—Ar.sup.3—(Ar.sup.4).sub.p—(Ar.sup.5).sub.q—(Ar.sup.6).sub.r   (I), wherein k, m, q, r are independently from each other 0, 1 or 2, p is 1, 2 or 3, wherein 2≤k+m+q+r+p≤11, Ar.sup.1 to Ar.sup.6 are independently selected from a substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, a substituted or unsubstituted C.sub.6 to C.sub.30 aryl or a substituted or unsubstituted C.sub.3 to C.sub.30 heteroaryl, a substituted or unsubstituted fluorene, or a fused ring system comprising 2 to 6 substituted or unsubstituted 5- to 7-member rings and the rings are selected from the group comprising (i) unsaturated 5- to 7-member ring of a heterocycle, (ii) 5- to 6-member of an aromatic heterocycle, (iii) unsaturated 5- to 7-member ring of a non-heterocycle, (iv) 6-member ring of an aromatic non-heterocycle; wherein the substituents are selected from the group H, D, C.sub.1 to C.sub.12 alkyl, unsubstituted C.sub.6 to C.sub.18 aryl, unsubstituted C.sub.3 to C.sub.18 heteroaryl, a fused ring system comprising 2 to 6 unsubstituted 5- to 7-member rings and the rings are selected from the group comprising unsaturated 5- to 7-member ring of a heterocycle, 5- to 6-member of an aromatic heterocycle, unsaturated 5- to 7-member ring of a non-heterocycle, and 6-member ring of an aromatic non-heterocycle; the metal complex has the formula (II):
M.sup.n⊕(L.sub.θ).sub.n   (II), wherein M is a metal ion, n is the valency of M, wherein n is an integer from 1 to 4, L is a ligand; and wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected the same or selected different.

3. The organic electronic device according to claim 1 or 2, wherein the hole injection layer is non-emissive.

4. The organic electronic device according to claim 1 or 2, wherein the hole injection layer is arranged adjacent to the anode layer, alternatively in direct contact with the anode layer.

5. The organic electronic device according to claim 1 or 2, wherein the HOMO level of the organic matrix compound (OMC) is further away from vacuum level than the HOMO level of N4,N4′″-di(naphthalen-1-yl)-N4,N4′″-diphenyl-[1,1′:4′,1″:4″,1′″-quaterphenyl]-4,4′″-diamine when determined under the same conditions.

6. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) fulfills the following equation:
−7 eV <HOMO level (OMC) <−4.85 eV; wherein the HOMO level is calculated with the program package TURBOMOLE V6.5.

7. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) have the formula (I):
(Ar.sup.1).sub.k—(Ar.sup.2).sub.m—Ar.sup.3—(Ar.sup.4).sub.p—(Ar.sup.5).sub.q—(Ar.sup.6).sub.r   (I), wherein k, m, q, r are independently from each other 0, 1 or 2, p is 1, 2 or 3, wherein 2≤k+m+q+r+p≤11, Ar.sup.1 to Ar.sup.6 are independently selected from substituted or unsubstituted biphenylene, substituted or unsubstituted fluorene, substituted or unsubstituted naphthalene, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted triphenylene, substituted or unsubstituted tetracene, substituted or unsubstituted tetraphene, substituted or unsubstituted dibenzofurane, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted xanthene, substituted or unsubstituted carbazole, substituted or unsubstituted azepine, substituted or unsubstituted dibenzo[b,f]azepine, 9,9′-spirobi[fluorene], substituted or unsubstituted spiro[fluorene-9,9′-xanthene], substituted or unsubstituted 9,14-dihydrodibenzo[2,3:6,7]azepino[4,5-b]indole, or a substituted or unsubstituted aromatic fused ring system comprising at least three substituted or unsubstituted aromatic rings selected from the group comprising substituted or unsubstituted non-hetero, substituted or unsubstituted hetero 5-member rings, substituted or unsubstituted 6-member rings or substituted or unsubstituted 7-member rings, substituted or unsubstituted fluorene, or a fused ring system comprising 2 to 6 substituted or unsubstituted 5- to 7-member rings and the rings are selected from the group comprising (i) unsaturated 5- to 7-member ring of a heterocycle, (ii) 5- to 6-member of an aromatic heterocycle, (iii) unsaturated 5- to 7-member ring of a non-heterocycle, (iv) 6-member ring of an aromatic non-heterocycle, wherein the substituents are selected from the group H, D, C.sub.1 to C.sub.12 alkyl, unsubstituted C.sub.6 to C.sub.18 aryl, unsubstituted C.sub.3 to C.sub.18 heteroaryl, a fused ring system comprising 2 to 6 unsubstituted 5- to 7-member rings and the rings are selected from the group comprising unsaturated 5- to 7-member ring of a heterocycle, 5- to 6-member of an aromatic heterocycle, unsaturated 5- to 7-member ring of a non-heterocycle, and 6-member ring of an aromatic non-heterocycle; and wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected the same or selected different.

8. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) of the hole injection layer and/or the emitter matrix compound (EMC) has a molecular weight Mw of ≥400 and ≤2000 g/mol.

9. The organic electronic device according to claim 1 or 2, wherein M is selected from the group comprising a metal ion wherein the corresponding metal has an electronegativity value according to Allen of less than 2.4, an alkali, alkaline earth, rare earth or transition metal, a metal with an atomic mass ≥24 Da, or a metal with an atomic mass ≥24 Da and M has an oxidation number ≥2.

10. The organic electronic device according to claim 1 or 2, wherein the metal complex has a molecular weight Mw of ≥287 and ≤2000 g/mol.

11. The organic electronic device according to claim 1 or 2, wherein L is selected from a group comprising at least three carbon atoms, alternatively at least four carbon atoms, or at least two oxygen atoms or one oxygen and one nitrogen atom, two to four oxygen atoms, two to four oxygen atoms and zero to two nitrogen atoms, or at least one or more groups selected from halogen, F, CN, substituted or unsubstituted C.sub.1 to C.sub.6 alkyl, substituted or unsubstituted C.sub.1 to C.sub.6 alkoxy, alternatively two or more groups selected from halogen, F, CN, substituted or unsubstituted C.sub.1 to C.sub.6 alkyl, substituted or unsubstituted C.sub.1 to C.sub.6 alkoxy, at least one or more groups selected from halogen, F, CN, substituted C.sub.1 to C.sub.6 alkyl, substituted C.sub.1 to C.sub.6 alkoxy, alternatively two or more groups selected from halogen, F, CN, perfluorinated C.sub.1 to C.sub.6 alkyl, perfluorinated C.sub.1 to C.sub.6 alkoxy, one or more groups selected from substituted or unsubstituted C.sub.1 to C.sub.6 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, or substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl, wherein the substituents are selected from D, C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.6, COOR.sup.6, halogen, F or CN; wherein R.sup.6 is selected from C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy.

12. The organic electronic device according to claim 1 or 2, wherein the metal complex according to formula (II) is non-emissive.

13. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) have the formula (I):
(Ar.sup.1).sub.k—(Ar.sup.2).sub.m—Ar.sup.3—(Ar.sup.4).sub.p—(Ar.sup.5).sub.q—(Ar.sup.6).sub.r   (I), wherein k, m, q, r are independently from each other 0, 1 or 2, p is 1, 2 or 3, wherein 2≤k+m+q+r+p≤11, Ar.sup.1 to Ar.sup.6 are independently selected from substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, substituted or unsubstituted C.sub.6 to C.sub.30 aryl, substituted or unsubstituted C.sub.3 to C.sub.30 heteroaryl, a substituted or unsubstituted fluorene, or a fused ring system comprising 2 to 6 substituted or unsubstituted 5- to 7-member rings and the rings are selected from the group comprising (i) unsaturated 5- to 7-member ring of a heterocycle, (ii) 5- to 6-member of an aromatic heterocycle, (iii) unsaturated 5- to 7-member ring of a non-heterocycle, (iv) 6-member ring of an aromatic non-heterocycle; Ar.sup.2 if k=1, Ar.sup.3, Ar.sup.4 if q=1, Ar.sup.5 if r=1: are independently selected from substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, substituted or unsubstituted C.sub.6 to C.sub.30 arylene, substituted or unsubstituted C.sub.3 to C.sub.30 heteroarylene, substituted or unsubstituted biphenylene, substituted or unsubstituted fluorene, substituted or unsubstituted naphthalene, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted triphenylene, substituted or unsubstituted tetracene, substituted or unsubstituted tetraphene, substituted or unsubstituted dibenzofurane, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted xanthene, substituted or unsubstituted carbazole, substituted or unsubstituted azepine, substituted or unsubstituted dibenzo[b,f]azepine, 9,9′-spirobi[fluorene], substituted or unsubstituted spiro[fluorene-9,9′-xanthene], substituted or unsubstituted 9,14-dihydrodibenzo[2,3:6,7]azepino[4,5-b]indole, or a substituted or unsubstituted aromatic fused ring system comprising at least three substituted or unsubstituted aromatic rings selected from the group comprising substituted or unsubstituted non-hetero, substituted or unsubstituted hetero 5-member rings, substituted or unsubstituted 6-member rings or substituted or unsubstituted 7-member rings; Ar.sup.2 if k=0, Ar.sup.3 if m=0 and k=0, Ar.sup.4 if q and r=0, Ar.sup.5 if r=0: are independently selected from substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, substituted or unsubstituted C.sub.6 to C.sub.30 aryl, substituted or unsubstituted C.sub.3 to C.sub.30 heteroaryl, substituted or unsubstituted biphenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted naphthalenyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted perylenyl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted tetracenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted xanthenyl, substituted or unsubstituted carbazole, substituted or unsubstituted azepine, substituted or unsubstituted dibenzo[b,f]azepine, 9,9′-spirobi[fluorenyl], substituted or unsubstituted spiro[fluorenyl-9,9′-xanthene], substituted or unsubstituted 9,14-dihydrodibenzo[2,3:6,7]azepino[4,5-b]indole, or a substituted or unsubstituted aromatic fused ring system comprising at least three substituted or unsubstituted aromatic rings selected from the group comprising substituted or unsubstituted non-hetero, substituted or unsubstituted hetero 5-member rings, substituted or unsubstituted 6-member rings or substituted or unsubstituted 7-member rings; 1 wherein the substituents are selected from the group H, D, C.sub.1 to C.sub.12 alkyl, unsubstituted C.sub.6 to C.sub.18 aryl, unsubstituted C.sub.3 to C.sub.18 heteroaryl, a fused ring system comprising 2 to 6 unsubstituted 5- to 7-member rings and the rings are selected from the group comprising unsaturated 5- to 7-member ring of a heterocycle, 5- to 6-member of an aromatic heterocycle, unsaturated 5- to 7-member ring of a non-heterocycle, and 6-member ring of an aromatic non-heterocycle; and wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected the same or selected different, and wherein the metal complex has the formula (II).

14. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected from the group of compounds comprising at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings, at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, at least ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings, at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, at least 3 or 4 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings, at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, at least an aromatic fused ring systems comprising heteroaromatic rings are unsubstituted, or at least ≥1 to ≤3 unsubstituted unsaturated 5- to 7-member ring of a heterocycle.

15. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected from the group of compounds comprising a substituted or unsubstituted aromatic fused ring systems with at least ≥2 to ≤6fused aromatic rings selected from the group comprising substituted or unsubstituted non-hetero aromatic rings, substituted or unsubstituted hetero 5-member rings, substituted or unsubstituted 6-member rings substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle; or an unsubstituted aromatic fused ring systems with at least ≥2 to ≤6fused aromatic rings selected from the group comprising unsubstituted non-hetero aromatic rings, unsubstituted hetero 5-member rings, unsubstituted 6-member rings or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.

16. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected from the group of compounds comprising at least ≥1 to <6 substituted or unsubstituted aromatic fused ring systems with at least one unsaturated 5-member ring, at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems with at least one unsaturated 6-member ring, at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems with at least one unsaturated 7-member ring, at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems with at least one unsaturated 5-member ring comprises at least 1 to 3 hetero-atoms or at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems with at least one unsaturated 7-member ring comprises at least 1 to 3 hetero-atoms.

17. The organic electronic device according to claim 1 or 2, wherein for the organic matrix compound (OMC) and the emitter matrix compound (EMC) comprise the hetero-atom is selected from the group comprising O, S, N, B, P or Si.

18. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) is free of hetero-atoms which are not part of an aromatic ring or part of an unsaturated 7-member-ring.

19. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) and the emitter matrix compound (EMC) are selected from compounds compring: at least ≥6 to ≤12 aromatic rings; at least ≥4 to ≤11, non-hetero aromatic rings; at least ≥1 to ≤4hetero aromatic 5-member-rings; at least 1 or 2 unsaturated 5- to 7-member-ring of a heterocycle, at least ≥6 to ≤12 aromatic rings, wherein therefrom at least ≥4 to ≤11are non-hetero aromatic rings and at least ≥1 to ≤4aromatic rings are hereto aromatic rings, wherein the total number of non-hetero aromatic rings and hetero aromatic rings in total does not exceed 12 aromatic rings, at least ≥6 to ≤12, preferably ≥7 to ≤11, further preferred ≥8 to ≤10 or 9 aromatic rings, wherein therefrom at least ≥4 to ≤11, preferably ≥5 to ≤10, further preferred ≥6 to ≤9 or in addition preferred 7 or 8 are non-hetero aromatic rings, and at least ≥1 to ≤4, preferably 2 or 3 aromatic rings are hetero aromatic rings, wherein the total number of non-hetero aromatic rings and hetero aromatic rings in total does not exceed 12 aromatic rings; and the hole transport compound or the hole transport compound according to formula I is selected from the group of compounds comprising at least ≥1 to ≤4 hetero aromatic 5-member-rings, or at least 1 or 2 unsaturated 5- to 7-member-ring of a heterocycle.

20. The organic electronic device according to claim 1 or 2, wherein for formula (I): Ar.sup.3 is selected from D1 to D17: ##STR00096## ##STR00097## ##STR00098## .sub.Arl is selected from D7 to D15 and D17, if m <0 and k >0, or is selected from D7 to D15 and D17, if k >0 and m=0, or is selected from D1 to D6, if k >1; .sub.Ar2 is selected from D1 .sub.to D6, if m .sub.>0 and k .sub.>0; or is selected from D7 to D15 and D17, if m >0 and k=0; Ar.sup.4 is selected from D1 to D6, if q >0, or is selected from D1 to D6, if q=0 and r >0; or is selected from D7 to D15 and D17, if q and r=0; Ar.sup.5 is selected from D1 to D6, if q >0 and r >0, or is selected from D7 to D15 and D17, if q >0 and r=0; Ar6 is selected from D7 to D15 and D17, if r .sub.>0, .sub.q >0, or is selected from D7 to D15 and D17, if r >0, q=0, or is selected from D1 to D6, if r >1.

21. The organic electronic device according to claim 1 or 2, wherein the organic matrix compound (OMC) or the emitter matrix compound (EMC) according to formula (I) is selected from F1 to F13: ##STR00099## ##STR00100## ##STR00101##

22. The organic electronic device according to claim 1 or 2, wherein n is an integer from 1 to 4.

23. The organic electronic device according to claim 1 or 2, wherein the metal complex is selected from the following formulas (IIa) to (IIe): ##STR00102## wherein M is a metal ion; n is the valency of M, wherein n is an integer from 1 to 4; A.sup.1 and A.sup.2 are independently selected from substituted or unsubstituted C.sub.1 to C,2 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl; A.sup.3 is selected from H, D, substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl; wherein the substituents of A.sup.1, A.sup.2 or A.sup.3 are independently selected from D, C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated Cl to C.sub.6 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.1, COOR.sup.1, halogen, F or CN, wherein R.sup.I is selected from C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy.

24. The organic electronic device according to claim 23, wherein at least one of A.sup.1, A.sup.2 and A.sup.3 comprises a substituent, wherein at least one of the substituents of A.sup.1, A.sup.2 and A.sup.3 is independently selected from C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.1, COOR.sup.1, halogen, F or CN.

25. The organic electronic device according to claim 1 or 2, wherein L is independently selected from G1 to G64: ##STR00103## ##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111##

26. The organic electronic device according to claim 1 or 2, wherein the hole injection layer comprises a first sub-layer comprising the metal complex of formula (II) and a second sub-layer comprising the organic matrix compound (OMC), wherein the first sub-layer is arranged closer to the anode layer and the second sub-layer is arranged closer to the at least one emission layer.

27. The organic electronic device according to claim 1 or 2, wherein the hole injection layer comprises a first sub-layer comprising the metal complex of formula (II) and a second sub-layer comprising the organic matrix compound (OMC) and the metal complex, wherein the first sub-layer is arranged closer to the anode layer and the second sub-layer is arranged closer to the at least one emission layer.

28. The organic electronic device according to claim 26 or 27, wherein the organic electronic device further comprises a hole transport layer, wherein the hole transport layer is arranged between the hole injection layer and the at least one emission layer.

29. The organic electronic device according to claim 1 or 2, wherein the hole transport layer comprises an organic matrix compound (OMC), wherein the organic matrix compound (OMC) in the hole injection layer and hole transport layer is selected different or selected the same.

30. The organic electronic device according to claim 1 or 2, wherein the hole injection layer and hole transport layer comprise an organic matrix compound (OMC) and the at least one emission layer comprises an emitter matrix compound (EMC) of formula (I), wherein in formula (I) the AP group is selected the same.

31. The organic electronic device according to claim 1 or 2, wherein the organic electronic device is a light emitting device or a display device.

Description

DESCRIPTION OF THE DRAWINGS

[0504] The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pertinent field can be applied without limitations.

[0505] Additional details, characteristics and advantages of the object are disclosed in the dependent claims and the following description of the respective figures which in an exemplary fashion show preferred embodiments according to the invention. Any embodiment does not necessarily represent the full scope, however, and reference is made therefore to the claims and herein for interpreting the scope. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention as claimed.

[0506] FIG. 1 is a schematic sectional view of an organic electronic device, according to an exemplary embodiment of the present invention;

[0507] FIG. 2 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention;

[0508] FIG. 3 is a schematic sectional view of an OLED, according to an exemplary embodiment of the present invention.

[0509] Hereinafter, the figures are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.

[0510] Herein, when a first element is referred to as being formed or disposed “on” or “onto” a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed “directly on” or “directly onto” a second element, no other elements are disposed there between.

[0511] FIG. 1 is a schematic sectional view of an organic electronic device 100, according to an exemplary embodiment of the present invention. The organic electronic device 100 includes a substrate 110, an anode layer 120 and a hole injection layer (HIL) (130). The HIL 130 is disposed on the anode layer 120. Onto the HIL 130, an emission layer (EML) 150, and a cathode layer 190 are disposed.

[0512] The hole injection layer (HIL) 130 may comprise a first and a second sub-layer wherein the first sub-layer is disposed on the anode and the second sub-layer is disposed on the first sub-layer. The photoactive layer (PAL) 170 is disposed on the second-sub-layer.

[0513] FIG. 2 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate 110, an anode layer 120 and a hole injection layer (HIL) 130, The HIL 130 is disposed on the anode layer 120. Onto the HIL 130, a hole transport layer (HTL) 140, an emission layer (EML) 150, an electron transport layer (ETL) 160, an electron injection layer (EIL) 180 and a cathode layer 190 are disposed. Instead of a single electron transport layer 160, optionally an electron transport layer stack (ETL) can be used.

[0514] The hole injection layer (HIL) 130 may comprise a first and a second sub-layer wherein the first sub-layer is disposed on the anode and the second sub-layer is disposed on the first sub-layer. The hole transport layer (HTL) 140 is disposed on the second-sub-layer.

[0515] FIG. 3 is a schematic sectional view of an OLED 100, according to another exemplary embodiment of the present invention. FIG. 2 differs from FIG. 1 in that the OLED 100 of FIG. 2 comprises an electron blocking layer (EBL) 145 and a hole blocking layer (HBL) 155.

[0516] Referring to FIG. 3, the OLED 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, an emission layer (EML) 150, a hole blocking layer (HBL) 155, an electron transport layer (ETL) 160, an electron injection layer (EIL) 180 and a cathode layer 190.

[0517] While not shown in FIG. 1, FIG. 2 and FIG. 3, a sealing layer may further be formed on the cathode layer 190, in order to seal the organic electronic device 100. In addition, various other modifications may be applied thereto.

[0518] Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples.

DETAILED DESCRIPTION

[0519] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.

[0520] Organic matrix compound of formula (I), metal complexes of formula (II) and emitter matrix compound of formula (I) may be prepared as described in the literature.

Rate Onset Temperature

[0521] The rate onset temperature (TRO) is determined by loading 100 mg organic matrix compound into a VTE source. As VTE source a point source for organic materials may be used as supplied by Kurt J. Lesker Company (www.lesker.com) or CreaPhys GmbH (http://www.creaphys.com). The VTE source is heated at a constant rate of 15 K/min at a pressure of less than 10.sup.−5 mbar and the temperature inside the source measured with a thermocouple. Evaporation of the organic matrix compound is detected with a QCM detector which detects deposition of the organic matrix compound on the quartz crystal of the detector. The deposition rate on the quartz crystal is measured in Angstrom per second. To determine the rate onset temperature, the deposition rate is plotted against the VTE source temperature. The rate onset is the temperature at which noticeable deposition on the QCM detector occurs. For accurate results, the VTE source is heated and cooled three time and only results from the second and third run are used to determine the rate onset temperature.

[0522] To achieve good control over the evaporation rate of a metal complex of formula (II), the rate onset temperature may be in the range of ≥110 ° C. to ≤300 ° C., preferably ≥115 ° C. to ≤290° C. If the rate onset temperature is too low the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is too high the evaporation rate may be too low which may result in low tact time and/or decomposition of the metal complex of formula (II) in VTE source may occur due to prolonged exposure to elevated temperatures.

[0523] To achieve good control over the evaporation rate of the organic matrix compound and/or emitter matrix compound of the present invention, the rate onset temperature may be in the range of 120 to 300 ° C. If the rate onset temperature is too low the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is too high the evaporation rate may be too low which may result in low tact time.

[0524] The rate onset temperature is an indirect measure of the volatility of a compound. The higher the rate onset temperature the lower is the volatility of a compound.

HOMO and LUMO

[0525] The HOMO level and LUMO level are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized geometries and the HOMO level and LUMO levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6−31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy may be selected. The HOMO and LUMO levels are recorded in electron volt (eV).

[0526] General procedure for fabrication of OLEDs comprising a hole injection layer and an emission layer comprising a fluorescent blue emitter

[0527] For OLEDs, see Examples 1 to 11 and comparative examples 1 to 3 in Table 4 and 5, a 15Ω/cm.sup.2glass substrate with 90 nm ITO (available from Corning Co.) was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and washed again with UV ozone for 30 minutes, to prepare the anode layer.

[0528] Then, 70 vol.-% organic matrix compound and 30 vol.-% metal complex were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm. The composition of the hole injection layer can be seen in Table 4 and 5. In comparative examples 1 to 3, 70 vol.-% organic matrix compound and 30 vol.-% HAT-CN were co-deposited in vacuum on the anode layer to form a HIL having a thickness of 10 nm.

[0529] Then, the organic matrix compound was vacuum deposited on the HIL, to form a HTL having a thickness of 128 nm. The organic matrix compound in the HTL is selected the same as the organic matrix compound in the HIL. The organic matrix compound can be seen in Table 4 and 5.

[0530] Then N,N-bis(4-(dibenzo [b,d] furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4- amine (CAS 1198399−61−9) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.

[0531] Then 97 vol.-% EMC-6 as emitter matrix compound and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue emitter dopant were deposited on the EBL, to form a blue-emitting EML with a thickness of 20 nm.

[0532] Then a hole blocking layer was formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer EML.

[0533] Then the electron transporting layer having a thickness of 31 nm was formed on the hole blocking layer by depositing 50 wt.-% 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile and 50 wt.-% of LiQ

[0534] Then A1 was evaporated at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar to form a cathode layer with a thickness of 100 nm on the electron transporting layer.

[0535] The OLED stack was protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed which may include a getter material for further protection.

General Procedure for Fabrication of OLEDs Comprising a Hole Injection Layer and an Emission Layer Comprising a Phosphorescent Green Emitter

[0536] For OLEDs, see Examples 12 and 13 and comparative examples 4 and 5 in Table 5, a 15Ω/cm.sup.2 glass substrate with 90 nm ITO (available from Corning Co.) was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and washed again with UV ozone for 30 minutes, to prepare the anode layer.

[0537] Then, 70 vol.-% organic matrix compound and 30 vol.-% metal complex were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm. The composition of the hole injection layer can be seen in Table 6. In comparative examples 4 and 5, 70 vol.-% organic matrix compound and 30 vol.-% HAT-CN were co-deposited in vacuum on the anode layer to form a HIL having a thickness of 10 nm.

[0538] Then, the organic matrix compound was vacuum deposited on the HIL, to form a HTL having a thickness of 165 nm. The organic matrix compound in the HTL is selected the same as the organic matrix compound in the HIL. The organic matrix compound can be seen in Table 6.

[0539] Then, 90 vol.-% GH-1 and 10 vol.-% GD-1 were co-deposited in vacuum on the HTL, to form a green-emitting emission layer with a thickness of 40 nm. GH-1 comprises EMC-4 and GET-1 in a molar ratio of 1:1. The formulas of GET-1 and GD-1 are shown below:

##STR00053##

[0540] Then a hole blocking layer was formed with a thickness of 25 nm by depositing 2,4-diphenyl-6-(3′-(triphenylen-2-yl)-[1,1′-biphenyl]-3-yl)-1,3,5-triazine on the emission layer EML.

[0541] Then the electron transporting layer having a thickness of 10 nm was formed on the hole blocking layer by depositing 99 vol.-% 3-Phenyl-3H-benzo[b]dinaphtho[2,1-d:1′,2′-f]pho sphepine-3-oxide and 1 vol.-% Yb.

[0542] Then A1 was evaporated at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar to form a cathode layer with a thickness of 100 nm on the electron transporting layer.

[0543] The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed which may include a getter material for further protection.

General Procedure for Fabrication of OLEDs Comprising a Hole Injection Layer Comprising a First and Second Sub-Layer

[0544] For OLEDs, see Examples 14 to 28 and comparative examples 6 to 11 in Table 7, a 15Ω/cm.sup.2 glass substrate with 90 nm ITO (available from Corning Co.) was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and washed again with UV ozone for 30 minutes, to prepare the anode layer.

[0545] Then, the hole injection layer comprising a first and a second sub-layer was vacuum deposited on the anode layer. First, a metal complex was vacuum deposited on the anode layer to form a first sub-layer with a thickness of 3 or 5 nm, see Table 7. In comparative examples 6 to 11, HAT-CN was vacuum deposited on the anode layer to form a first sub-layer with a thickness of 3 or 5 nm, see Table 7.

[0546] Then, the organic matrix compound was vacuum deposited on the first sub-layer to form a second sub-layer with a thickness of 7 or 5 nm, see Table 7.

[0547] Then, an organic matrix compound was vacuum deposited on the hole injection layer to form a HTL. The organic matrix compound in the HTL is selected the same as the organic matrix compound in the HIL, see Table 7. The thickness is selected in such a way, that the thickness of the second sub-layer and the thickness of the HTL add up to 128 nm in total.

[0548] Then N,N-bis(4-(dibenzo [b,d] furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.

[0549] Then 97 vol.-% EMC-6 as emitter matrix compound and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue emitter dopant were deposited on the EBL, to form a blue-emitting EML with a thickness of 20 nm.

[0550] Then a hole blocking layer was formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer EML.

[0551] Then the electron transporting layer having a thickness of 31 nm was formed on the hole blocking layer by depositing 50 wt.-% 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile and 50 wt.-% of LiQ

[0552] Then A1 was evaporated at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar to form a cathode layer with a thickness of 100 nm on the electron transporting layer.

[0553] The OLED stack was protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed which may include a getter material for further protection.

[0554] To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing an operating voltage U in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between OV and 10V. To protect the instruments from damage, the measurement was stopped at 10 V.

Technical Effect

[0555] In order to investigate the usefulness of the inventive layer stack preferred materials were tested in view of their physical properties, see Tables 1 to 3.

[0556] In Table 1 are shown the HOMO levels calculated with program TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) and the rate onset temperatures TRO of organic matrix compounds of the present invention.

TABLE-US-00002 TABLE 1 Chemical formulas and physical properties of organic matrix compounds HOMO level T.sub.RO Name Chemical formula (eV) (° C.) 9-phenyl-10-(3′,4′,5′- triphenyl-[1,1′:2′,1″- terphenyl]-3-yl)anthracene OMC-1 [00054] −5.04 210 1,3-bis(10- phenylanthracen- 9-yl)benzene OMC-2 [00055] −5.08 230 9-phenyl-10-(3′-(9-phenyl- 9H-fluoren-9-yl)-[1,1′- biphenyl]-3-yl)anthracene OMC-3 [00056] −5.08 226 9-([1,1′-biphenyl]-3-yl)-9′- ([1,1′-biphenyl]-4-yl)- 9H,9′H-3,3′-bicarbazole OMC-4 [00057] −5.09 265 9-(4-(naphthalen-1- yl)phenyl)-10- phenylanthracene OMC-5 [00058] −5.1 approx. 130 2-(10-phenylanthracen-9- yl)dibenzo[b,d]furan OMC-6 [00059] −5.11 — 2-phenyl-8-(10- phenylanthracen-9- yl)dibenzo[b,d]furan OMC-7 [00060] −5.13 216 7-(3-(10-phenylanthracen-9- yl)phenyl)dibenzo[c,h] acridine OMC-8 [00061] −5.17 282 7-(4-(3,6-diphenyl-9H- carbazol-9- yl)phenyl)dibenzo[c,h] acridine OMC-9 [00062] −5.28 291 4,4′-Bis(carbazol-9-yl)- biphenyl OMC-10 [00063] −5.3 approx. 240 2,7-di([1,1′-biphenyl]-4- yl)spiro[fluorene-9,9′- xanthene] OMC-11 [00064] −5.38 242 7-(3-(9H-carbazol-9- yl)phenyl)dibenzo[c,h] acridine OMC-12 [00065] −5.42 214 4,4′,4″-(1,3,5- Benzenetriyl)tris [dibenzothiophene] OMC-13 [00066] −5.67 272

[0557] As can be seen in Table 1, the organic matrix compounds have rate onset temperatures suitable for mass production of organic electronic devices.

[0558] In Table 2 are shown rate onset temperatures T.sub.RO of metal complexes of formula (II).

TABLE-US-00003 TABLE 2 Metal complexes of formula (II) Name Chemical formula T.sub.RO (° C.) MC-1 Li TFSI 222 MC-2 K TFSI 236 MC-3 Cs TFSI 224 MC-4 Ag TFSI 258 MC-5 Mg (TFSI).sub.2 243 MC-6 Mn (TFSI).sub.2 229 MC-7 Sc (TFSI).sub.3 258 MC-8 Mg [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 166 MC-9 Zn [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 118 MC-10 Ag [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2] 232 MC-11 Ag [N(SO.sub.2C.sub.3F.sub.7).sub.2] 254 MC-12 Ag [N(SO.sub.2C.sub.4F.sub.9).sub.2] 262 MC-13 Ag [N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)] 230 MC-14 Cu [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 101 MC-15 Cu [N(SO.sub.2C.sub.3F.sub.7).sub.2].sub.2 118 MC-16 Cu [N(SO.sub.2CF.sub.3) (SO.sub.2C.sub.4F.sub.9)].sub.2 113 MC-17 Mg [N(SO.sub.2CF.sub.3) (SO.sub.2C.sub.4F.sub.9)].sub.2 124 MC-18 Mn [N(SO.sub.2CF.sub.3) (SO.sub.2C.sub.4F.sub.9)].sub.2 202 MC-19 Cu [N(SO.sub.2CH.sub.3) (SO.sub.2C.sub.4F.sub.9)].sub.2 179 MC-20 Ag [N(SO.sub.2CH.sub.3) (SO.sub.2C.sub.4F.sub.9)] — MC-21 [00067] 254 MC-22 [00068] 238 MC-23 [00069] 262 MC-24 [00070] 180 MC-25 [00071] — MC-26 [00072] 167 MC-27 [00073] 282 MC-28 [00074] 263 MC-29 [00075] 194 MC-30 [00076] 190 MC-31 [00077] 128 MC-32 [00078] 196 MC-33 [00079] 105 MC-34 [00080] 187 MC-35 [00081] 194

[0559] As can be seen in Table 2, the metal complexes of formula (II) have rate onset temperatures suitable for mass production of organic electronic devices.

[0560] In Table 3 are shown the HOMO levels calculated with program TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) and the rate onset temperatures TRO of emitter matrix compounds of the present invention.

TABLE-US-00004 TABLE 3 Chemical formulas and physical properties of emitter matrix compounds HOMO level T.sub.RO Name Chemical formula (eV) (° C.) 9-phenyl-10-(3′,4′,5′- triphenyl-[1,1′:2′,1″- terphenyl]-3-yl)anthracene EMC-1 [00082] −5.04 210 1,3-bis(10-phenylanthracen- 9-yl)benzene EMC-2 [00083] −5.08 230 9-phenyl-10-(3′-(9-phenyl- 9H-fluoren-9-yl)-[1,1′- biphenyl]-3-yl)anthracene EMC-3 [00084] −5.08 226 9-([1,1′-biphenyl]-3-yl)-9′- ([1,1′-biphenyl]-4-yl)- 9H,9′H-3,3′-bicarbazole EMC-4 [00085] −5.09 265 9-(4-(naphthalen-1- yl)phenyl)-10- phenylanthracene EMC-5 [00086] −5.1 approx. 130 2-(10-phenylanthracen-9- yl)dibenzo[b,d]furan EMC-6 [00087] −5.11 — 2-phenyl-8-(10- phenylanthracen-9- yl)dibenzo[b,d]furan EMC-7 [00088] −5.13 216 7-(3-(10-phenylanthracen-9- yl)phenyl)dibenzo[c,h] acridine EMC-8 [00089] −5.17 282 7-(4-(3,6-diphenyl-9H- carbazol-9- yl)phenyl)dibenzo[c,h] acridine EMC-9 [00090] −5.28 291 4,4′-Bis(carbazol-9-yl)- biphenyl EMC-10 [00091] −5.3 approx. 240 2,7-di([1,1′-biphenyl]-4- yl)spiro[fluorene-9,9′- xanthene] EMC-11 [00092] −5.38 242 7-(3-(9H-carbazol-9- yl)phenyl)dibenzo[c,h] acridine EMC-12 [00093] −5.42 214 4,4′,4″-(1,3,5- Benzenetriyl)tris [dibenzothiophene] EMC-13 [00094] −5.67 272

[0561] As can be seen in Table 3, the emitter matrix compounds have rate onset temperatures suitable for mass production of organic electronic devices.

[0562] In Table 4 are shown operating voltages at 10 mA/cm.sup.2 in OLEDs comprising a hole injection layer comprising 70 vol.-% organic matrix compound OMC-10 and 30 vol.-% metal complex of formula (II) and an emission layer comprising 97 vol.-% emitter matrix compound EMC-6 and 3 vol.-% fluorescent blue emitter dopant. OMC-10 has a HOMO level of −5.30 eV. The emitter matrix compound EMC-6 has a HOMO level of −5.13 eV.

[0563] The offset between HOMO level of the emitter matrix compound and the HOMO level of the organic matrix compound is 0.17 eV.

TABLE-US-00005 TABLE 4 Performance of OLEDs comprising a fluorescent blue emitter and emitter matrix compound EMC-6 Organic HOMO level U at 10 matrix (EMC)-HOMO mA/ compound level Metal cm.sup.2 (OMC) (OMC) [eV] complex [V] Comparative OMC-10 0.17 HAT-CN >10 example 1 Example 1 OMC-10 0.17 Cu(TFSI).sub.2 6.9 Example 2 OMC-10 0.17 MC-24 6.3 Example 3 OMC-10 0.17 MC-6 5.3 Example 4 OMC-10 0.17 MC-27 5.4 Example 5 OMC-10 0.17 MC-29 5.2

[0564] In comparative example 1, HAT-CN, a state of the art material, is used at a concentration of 30 vol.-%. HAT-CN has the formula shown below:

##STR00095##

[0565] HAT-CN has a HOMO of −8.83 eV. The operating voltage is over 10 V.

[0566] In example 1, the hole injection layer comprises Cu(TFSI).sub.2as metal complex. The operating voltage is substantially improved to 6.9 V.

[0567] In example 2, the hole injection layer comprises a different Cu(II) complex, namely MC-24. Compared to example 1, the TFSI ligand has been replaced by an amide ligand comprising one trifluoro methyl and one substituted aryl group. The operating voltage is further improved to 6.3 V.

[0568] In example 3, the hole injection layer comprises MC-6. Compared to example 1, the Cu(II) cation has been replaced by a Mn(II) cation. The operating voltage compared to example 1 is improved from 6.9 to 5.3 V.

[0569] In example 4, the hole injection layer comprises a Mg complex. Compared to example 2, Cu(II) cation has been replaced by Mg(II) cation. The operating voltage is improved from 6.3 to 5.4 V.

[0570] In example 5, the hole injection layer comprises a Zn(II) complex. Compared to example 4, the Mg(II) cation has been replaced by a Zn(II) cation and the amide ligand has been replaced by a ligand comprising an N-aryl group. The operating voltage is still within the range acceptable for mass production.

[0571] In Table 5 are shown operating voltages at 10 mA/cm.sup.2 in OLEDs comprising a fluorescent blue emitter and a hole injection layer comprising 70 vol.-% organic matrix compound and 30 vol.-% metal complex of formula (II) and an emission layer comprising 97 vol.-% emitter matrix compound EMC-6 and 3 vol.-% fluorescent blue emitter.

[0572] The emitter matrix compound EMC-6 has a HOMO level of −5.13 eV.

TABLE-US-00006 TABLE 5 Performance of OLEDs comprising a fluorescent blue emitter and emitter matrix compound EMC-6 Organic HOMO HOMO level U at 10 matrix level (EMC)-HOMO mA/ compound (OMC) level (OMC) Metal cm.sup.2 (OMC) [eV] [eV] complex [V] Comparative OMC-5 −5.10 −0.03 HAT-CN >10 example 2 Comparative OMC-13 −5.67 0.54 HAT-CN >10 example 3 Example 6 OMC-5 −5.10 −0.03 MC-29 4.1 Example 7 OMC-6 −5.13 0 MC-29 4.1 Example 8 OMC-7 −5.13 0 MC-29 5.1 Example 9 OMC-9 −5.28 0.15 MC-29 5.7 Example 10 OMC-10 −5.30 0.17 MC-29 5.9 Example 11 OMC-13 −5.67 0.54 MC-29 7.0

[0573] In comparative example 2, the hole injection layer comprises organic matrix compound OMC-5 and 30 vol.-% HAT-CN. HAT-CN is free of metal complex. OMC-5 comprises an anthracene group. The HOMO level of OMC-5 is −5.10 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is −0.03 eV. The operating voltage is over 10 V.

[0574] In comparative example 3, the hole injection layer comprises organic matrix compound OMC-13 and 30 vol.-% HAT-CN. OMC-13 comprises three dibenzofuranyl groups. The HOMO level is −5.67 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.54 eV. The operating voltage is over 10 V.

[0575] In example 6, the hole injection layer comprises OMC-5 and metal complex MC-29. The operating voltage is reduced substantially to 4.1 V.

[0576] In example 7, the hole injection layer comprises OMC-6 and MC-29. OMC-6 comprises an anthracene and a dibenzofuranyl group. The same compound is used in the hole injection layer and in the emission layer. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0 eV. The operating voltage is unchanged at 4.1 V.

[0577] In example 8, the hole injection layer comprises OMC-7 and MC-29. OMC-7 comprises an anthracene and a dibenzofuranyl group. The HOMO level is −5.13 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0 eV. The operating voltage is a little bit higher than in example 7. However, the operating voltage is substantially reduced compared to comparative examples 2 and 3.

[0578] In example 9, the hole injection layer comprises OMC-9 and MC-29. OMC-9 comprises a dibenzoacridine and a carbazole group. The HOMO level is −5.28 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is increased to 0.15 eV. The operating voltage is a little bit higher than in example 8. However, the operating voltage is substantially reduced compared to comparative examples 2 and 3.

[0579] In example 10, the hole injection layer comprises OMC-10 and MC-29. OMC-10 comprises a two carbazole groups. The HOMO level is −5.30 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is increased to 0.17 eV. The operating voltage is still substantially reduced compared to comparative examples 2 and 3.

[0580] In example 11, the hole injection layer comprises OMC-13 and MC-29. OMC-13 comprises three dibenzofuranyl groups. The HOMO level is −5.67 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is increased further to 0.54 eV. The operating voltage is a little bit higher than in example 10. However, the operating voltage is substantially reduced compared to comparative examples 2 and 3.

[0581] In Table 6 are shown operating voltages at 10 mA/cm.sup.2 in OLEDs comprising a phosphorescent green emitter and a hole injection layer comprising an organic matrix compound and 30 vol.-% metal complex of formula (II) and an emission layer comprising 70 vol.-% of a composition comprising EMC-4 and GET-1 in a molar ratio of 1:1 and 30 vol.-% of phosphorescent green emitter GD-1. If the emission layer comprises a composition of two or more emitter matrix compounds, the emitter matrix compound with the HOMO level closer to vacuum level is considered.

[0582] The emitter matrix compound EMC-4 has a HOMO level of −5.09 eV. For comparison, GET-1 has a HOMO level of −5.69 eV.

TABLE-US-00007 TABLE 6 Performance of OLEDs comprising a phosphorescent green emitter HOMO U Organic HOMO level at 10 matrix level (EMC)-HOMO mA/ compound (OMC) level Metal cm.sup.2 (OMC) [eV] (OMC) [eV] complex [V] Comparative OMC-5 −5.10 0.01 HAT-CN >10 example 4 Example 12 OMC-5 −5.10 0.01 MC-29 4.5 Comparative OMC-10 −5.30 0.21 HAT-CN >10 example 5 Example 13 OMC-10 −5.30 0.21 MC-29 6.3

[0583] In comparative example 4, the hole injection layer comprises organic matrix compound OMC-5 and 30 vol.-% HAT-CN. HAT-CN is free of metal complex. OMC-5 comprises an anthracene group. The HOMO level of OMC-5 is −5.10 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.01 eV. The operating voltage is over 10 V.

[0584] In example 12, the hole injection layer comprises OMC-5 and metal complex MC-29. The operating voltage is reduced substantially to 4.1 V.

[0585] In comparative example 5, the hole injection layer comprises organic matrix compound OMC-10 and 30 vol.-% HAT-CN. OMC-10 comprises two carbazole groups. The HOMO level of OMC-10 is −5.30 eV. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.21 eV. The operating voltage is over 10 V.

[0586] In example 13, the hole injection layer comprises OMC-10 and metal complex MC-29. The operating voltage is reduced substantially to 6.3 V.

[0587] In Table 7 are shown operating voltages at 10 mA/cm.sup.2 in OLEDs comprising a fluorescent blue emitter and a hole injection layer, wherein the hole injection layer comprises a first sub-layer consisting of metal complex of formula (II) and a second sub-layer consisting of organic matrix compound. The emission layer comprises 97 vol.-% emitter matrix compound EMC-6 and 3 vol.-% fluorescent blue emitter.

[0588] In comparative example 6, the first sub-layer comprises HAT-CN as a state-of-the-art hole injection material with a thickness of 3 nm. HAT-CN is free of metal complex. The second sub-layer comprises organic matrix compound OMC-6. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is −0.03 eV. The operating voltage is over 10 V.

[0589] In comparative example 7, the first sub-layer comprises HAT-CN and the second sub-layer comprises organic matrix compound OMC-7. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.15 eV. The operating voltage is over 10 V.

[0590] In comparative example 8, the first sub-layer comprises HAT-CN and the second sub-layer comprises organic matrix compound OMC-10. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.17 eV. The operating voltage is over 10 V.

[0591] In Example 14, the first sub-layer comprises metal complex MC-29 with a thickness of 3 nm. The second sub-layer comprises organic matrix compound OMC-6. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is −0.03 eV. The operating voltage is 4.0 V and thereby substantially improved over comparative example 6.

[0592] In Examples 15 to 17, the first sub-layer is the same as in Example 14. The second sub-layer comprises a range of organic matrix compounds with a HOMO level further away from vacuum level than OMC-6. The offset in HOMO level between the emitter matrix compound and the organic matrix compounds is in the range of 0 to 0.17 eV. In all examples, the operating voltage is substantially improved over comparative examples 6, 7 and 8.

[0593] In Examples 18 to 20, the first sub-layer comprises metal complex MC-27. MC-27 differs from MC-29 in the metal cation and ligand, see Table 2. The second sub-layer comprises a range of organic matrix compounds. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is in the range of −0.03 to 0.15 eV. In all examples, the operating voltage is substantially improved over comparative examples 6, 7 and 8.

[0594] In Example 21, the first sub-layer comprises metal complex MC-30. MC-30 differs from MC-29 in the metal cation and ligand, see Table 2. The second sub-layer comprises OMC-7. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.15 eV. The operating voltage is 6.6 V and thereby improved over comparative example 7.

[0595] In comparative examples 9 to 11, the first sub-layer comprises HAT-CN as a state-of-the-art hole injection material with a thickness of 5 nm. The second sub-layer comprises a range of organic matrix compounds. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is in the range of −0.03 to 0.17 eV. The operating voltage is over 10 V.

[0596] In Example 22, the first sub-layer comprises metal complex MC-29 with a thickness of 5 nm. The second sub-layer comprises organic matrix compound OMC-6. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is −0.03 eV. The operating voltage is 4.0 V and thereby substantially improved over comparative example 9. The performance is comparable to Example 14.

[0597] In Examples 23 to 25, the first sub-layer is the same as in Example 22. The second sub-layer comprises various organic matrix compounds with a HOMO level further away from vacuum level than OMC-6. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is in the range of 0 to 0.17 eV. In all examples, the operating voltage is substantially improved over comparative examples 9, 10 and 11.

[0598] In Examples 26 and 27, the first sub-layer comprises metal complex MC-27. MC-27 differs from MC-29 in the metal cation and ligand, see Table 2. The second sub-layer comprises various organic matrix compounds. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is in the range of 0 to 0.15 eV. In all examples, the operating voltage is substantially improved over comparative examples 9, 10 and 11.

[0599] In Example 28, the first sub-layer comprises metal complex MC-30. MC-30 differs from MC-29 in the metal cation and ligand, see Table 2. The second sub-layer comprises OMC-7. The offset in HOMO level between the emitter matrix compound and the organic matrix compound is 0.15 eV. The operating voltage is 5.4 V and thereby improved over comparative example 10.

[0600] In summary, a substantial improvement in operating voltage has been obtained for OLEDs comprising a hole injection layer according to invention.

[0601] A reduction in operating voltage may be beneficial for reduced power consumption and improved battery life, in particular in mobile devices.

TABLE-US-00008 TABLE 7 Performance of OLEDs comprising a hole injection layer (HIL), wherein the hole injection layer comprises a first and a second sub-layer HOMO level HOMO level Thickness (OMC) in Thickness (EMC) − Composition of first Composition second of second HOMO level U at 10 of first sub-layer of second sub-layer sub-layer Composition (OMC) mA/cm.sup.2 sub-layer [nm] sub-layer [eV] [nm] of HTL [eV] [V] Comparative HAT-CN 3 OMC-6 −5.10 7 OMC-6 −0.03 >10 example 6 Comparative HAT-CN 3 OMC-7 −5.28 7 OMC-7 0.15 >10 example 7 Comparative HAT-CN 3 OMC-10 −5.30 7 OMC-10 0.17 >10 example 8 Example 14 MC-29 3 OMC-6 −5.10 7 OMC-6 −0.03 4.0 Example 15 MC-29 3 OMC-5 −5.13 7 OMC-5 0 4.4 Example 16 MC-29 3 OMC-7 −5.28 7 OMC-7 0.15 4.5 Example 17 MC-29 3 OMC-10 −5.30 7 OMC-10 0.17 4.6 Example 18 MC-27 3 OMC-6 −5.10 7 OMC-6 −0.03 4.1 Example 19 MC-27 3 OMC-5 −5.13 7 OMC-5 0 4.7 Example 20 MC-27 3 OMC-7 −5.28 7 OMC-7 0.15 4.4 Example 21 MC-30 3 OMC-7 −5.28 7 OMC-7 0.15 6.6 Comparative HAT-CN 5 OMC-6 −5.10 5 OMC-6 −0.03 >10 example 9 Comparative HAT-CN 5 OMC-7 −5.28 5 OMC-7 0.15 >10 example 10 Comparative HAT-CN 5 OMC-10 −5.30 5 OMC-10 0.17 >10 example 11 Example 22 MC-29 5 OMC-6 −5.10 5 OMC-6 −0.03 4.0 Example 23 MC-29 5 OMC-5 −5.13 5 OMC-5 0 4.2 Example 24 MC-29 5 OMC-7 −5.28 5 OMC-7 0.15 4.4 Example 25 MC-29 5 OMC-10 −5.30 5 OMC-10 0.17 4.4 Example 26 MC-27 5 OMC-5 −5.13 5 OMC-5 0 4.9 Example 27 MC-27 5 OMC-7 −5.28 5 OMC-7 0.15 4.6 Example 28 MC-30 5 OMC-7 −5.28 5 OMC-7 0.15 5.4

[0602] It is apparent that the devices according to the invention show a much better performance than the comparative devices.

[0603] The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by way of example only and is not intended as limiting. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The invention's scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.