An Electroluminescent Device Comprising an Anode Layer, a Cathode Layer, a First Emission Layer, a Hole Injection Layer and a First Hole Transport Layer that Comprises a Compound Containing a Metal

Abstract

The present invention is directed to an electroluminescent device comprising an anode layer, a cathode layer, a first emission layer, a hole injection layer and a first hole transport layer that comprises a compound containing a metal.

Claims

1. An organic electroluminescent device comprising an anode layer, a cathode layer, a first emission layer (EML), a hole injection layer (HIL) and a first hole transport layer (HTL), wherein the hole injection layer comprises a compound of formula (I): wherein ##STR00107## M is a metal ion, n is an integer selected from 1 to 4, which corresponds to the oxidation number of M; AL is an ancillary ligand; m is an integer selected from 0, 1 or 2; L is a ligand of formula (II): ##STR00108## X is N or C-A.sup.3; Y.sup.1 and Y.sup.2 are independently selected from CO or SO.sub.2; A.sup.1 and A.sup.2 are independently selected from substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.19 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl, wherein the substituents on A.sup.1 and A.sup.2 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 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.1, COOR.sup.1, halogen, F or CN; A.sup.3 is selected from H, D, C.sub.1 to C.sub.4 alkyl, partially or perfluorinated C.sub.1 to C.sub.4 alkyl, CN, F, or A.sup.1 and A.sup.3 are bridged to form a cyclic ring; wherein at least two of the substituents in L of formula (II) are 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; wherein R.sup.1 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; the first emission layer comprises a compound of formula (III) and an organic emitter host compound: ##STR00109## wherein Z.sup.1, Z.sup.2 and Z.sup.3 are the same as or selected different from each other, and are each independently selected from the group comprising a monocyclic to polycyclic aromatic hydrocarbon ring or monocyclic to polycyclic aromatic hetero ring; Ar.sup.31 and Ar.sup.32 are the same as or selected different from each other, and are each independently and are each independently selected from the group comprising a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, or are bonded to an adjacent substituent to form a substituted or unsubstituted aromatic ring or a substituted or unsubstituted aliphatic ring; R.sup.31, R.sup.32 and R.sup.33 are the same as or selected different from each other, and are each independently selected from the group comprising hydrogen, deuterium, a substituted or unsubstituted alkyl group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, or adjacent substituents are bonded to each other to form a substituted or unsubstituted aromatic ring or a substituted or unsubstituted aliphatic ring, wherein one or more substituents selected from the group consisting of deuterium, an alkyl group having 1 to 6 carbon atoms, an alkyl silyl group having 1 to 30 carbon atoms, an aryl silyl group having 6 to 50 carbon atoms, an alkylamine group having 1 to 30 carbon atoms, an alkylarylamine group having 1 to 50 carbon atoms, an arylamine group having 6 to 50 carbon atoms, an aryl group having 6 to 30 carbon atoms, and a heteroaryl group having 2 to 30 carbon atoms, or a substituent to which two or more substituents selected from the group are linked, or adjacent substituents are bonded to each other to form an aliphatic hydrocarbon ring having 3 to 60 carbon atoms, which is unsubstituted or substituted with the substituent; r31, r32 and r33 are each an integer from 0, 1, 2, 3 or 4, and when r31 to r33 are 2 or higher, substituents in the parenthesis are the same as or selected different from each other; wherein the organic emitter host compound comprises: at least one condensed aromatic ring system consisting of at least 3 to 5 condensed aromatic rings, and selected from the group of at least 3 to 7 aromatic rings, or at least 3 to 7 heteroaromatic rings, wherein selected from the group of at least 2 to 7 of the aromatic rings, at least 3 to 7 of the heteroaromatic rings are condensed to form a fused aromatic ring system, or at least 3 to 7 of the heteroaromatic rings are condensed to form a fused heteroaromatic ring systems, and wherein the molecular weight Mw of the organic emitter host compound is in the range of 400 g/mol and 2000 g/mol; the first hole transport layer comprises an organic hole transport compound, wherein the organic hole transport compound comprises: at least 1 to 3 amine moieties, and at least 8 to 12 aromatic rings or heteroaromatic rings, and wherein the molecular weight Mw of the organic hole transport compound is in the range of 400 g/mol and 2000 g/mol; wherein the hole injection layer is arranged between the anode layer and the first hole transport layer; the first emission layer is arranged between the first hole transport layer and the cathode layer; and the first hole transport layer is arranged between the hole injection layer and the first emission layer.

2. The organic electroluminescent device according to claim 1, wherein the following equation is fulfilled: 0.8 eV [HOMO of organic emitter host compound-HOMO of organic hole transport compound]0 eV.

3. The organic electroluminescent device according to claim 1, wherein the ligand L of formula (II) comprises fluorine atoms selected from the group of at least 3 fluorine atoms, of at least 4 fluorine atoms, of at least 6 fluorine atoms or 3 to 60 fluorine atoms.

4. The organic electroluminescent device according to claim 1, wherein the ligand L of formula (II) is selected from the group of anionic ligands L of formula (IIb), (IIc) or (IId): ##STR00110## wherein A.sup.1 and A.sup.2 are independently selected from 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 and A.sup.2 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 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.1, COOR.sup.1, halogen, F or CN, wherein R.sup.1 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; A.sup.3 is selected from H, D, CN, C.sub.1 to C.sub.4 alkyl, partially or perfluorinated C.sub.1 to C.sub.4 alkyl, F, or A.sup.1 and A.sup.3 are bridged to form a cyclic ring, A.sup.3 is selected as to form a cyclic structure with either A.sup.1 or A.sup.2, A.sup.3 is selected as to form a cyclic structure with either A.sup.1 or A.sup.2 of 5- or 6-membered aliphatic or aromatic rings,-A.sup.3 is selected as to form a cyclic structure with either A.sup.1 or A.sup.2 of 5- or 6-membered aliphatic or aromatic rings whereby the ring comprise one or more heteroatoms, or A.sup.3 is selected as to form a cyclic structure with either A.sup.1 or A.sup.2 of 5- or 6-membered aliphatic or aromatic rings whereby the ring comprise one or more heteroatoms selected from the group comprising N, O and S; A.sup.4 is selected from substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.19 aryl, substituted or unsubstituted C.sub.2 to C.sub.20 heteroaryl, or substituted or unsubstituted 6-membered heteroaryl; A.sup.5 is selected from C.sub.1 to C.sub.6 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.9 heteroaryl, CN or CH.sub.3, wherein the substituents on A.sup.4 and A.sup.5 are independently selected from D, CN, C.sub.1 to C.sub.4 alkyl, partially or perfluorinated C.sub.1 to C.sub.4 alkyl, halogen or F; wherein at least two of the substituents in L are 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; wherein R.sup.1 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.

5. The organic electroluminescent device according to claim 1, wherein the ligand L of formula (IIb), (IIc) or (IId) are selected from G1 to G113: ##STR00111## ##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## ##STR00119## ##STR00120##

6. The organic electroluminescent device according to claim 1, wherein the compound of formula (I) is selected from the group comprising: Li TFSI, K TFSI, Cs TFSI, Ag TFSI, Mg(TFSI).sub.2, Mn(TFSI).sub.2, Sc(TFSI).sub.3, Na[N(SO.sub.2C.sub.4F.sub.9).sub.2], K[N(SO.sub.2C.sub.4F.sub.9).sub.2], Mg[N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2, Zn[N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2, Ag[N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2], Ag[N(SO.sub.2C.sub.3F.sub.7).sub.2], Ag[N(SO.sub.2C.sub.4F.sub.9).sub.2], Ag[N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)], Cs[N(SO.sub.2C.sub.4F.sub.9).sub.2], Mg[N(SO.sub.2C.sub.4F.sub.9).sub.2].sub.2, Ca[N(SO.sub.2C.sub.4F.sub.9).sub.2].sub.2, Ag[N(SO.sub.2C.sub.4F.sub.9).sub.2], Cu[N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2, Cu[N(SO.sub.2C.sub.3F.sub.7).sub.2].sub.2, Cu[N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)].sub.2, Cu [N(SO.sub.2C.sub.2H.sub.5)(SO.sub.2C.sub.4F.sub.9)].sub.2, Cu [N(SO.sub.2.sup.iC.sub.3H.sub.7)(SO.sub.2.sup.iC.sub.4F.sub.9)].sub.2, Cu [N(SO.sub.2.sup.iC.sub.3F.sub.7)(SO.sub.2.sup.iC.sub.4F.sub.9)].sub.2, Cu[N(SO.sub.2CH.sub.3)(SO.sub.2C.sub.4F.sub.9)].sub.2, Mg[N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)].sub.2, Mn[N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)].sub.2, Ag[N(SO.sub.2CH.sub.3)(SO.sub.2.sup.iC.sub.4F.sub.9)], ##STR00121## ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## wherein i denotes iso.

7. The organic electroluminescent device according to claim 1, wherein the organic hole transport compound is selected from a compound of formula (IVa) or of formula (IVb): ##STR00127## wherein: T.sup.1 to T.sup.5 are independently selected from a single bond, phenylene, biphenylene, terphenylene or naphthenylene; T.sup.6 is phenylene, biphenylene, terphenylene or naphthenylene; Ar.sup.1 to Ar.sup.5 are independently selected from substituted or unsubstituted C.sub.6 to C.sub.20 aryl, or substituted or unsubstituted C.sub.3 to C.sub.20 heteroarylene, substituted or unsubstituted biphenylene, substituted or unsubstituted fluorene, substituted 9-fluorene, substituted 9,9-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 9-phenylcarbazole, substituted or unsubstituted azepine, substituted or unsubstituted dibenzo[b,f]azepine, substituted or unsubstituted 9,9-spirobi[fluorene], substituted or unsubstituted spiro[fluorene-9,9-xanthene], 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 and/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 of Ar.sup.1 to Ar.sup.5 are selected the same or different from the group comprising H, D, F, C(O)R.sup.2, CN, Si(R.sup.2).sub.3, P(O)(R.sup.2).sub.2, OR.sup.2, S(O)R.sup.2, S(O).sub.2R.sup.2, substituted or unsubstituted straight-chain alkyl having 1 to 20 carbon atoms, substituted or unsubstituted branched alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cyclic alkyl having 3 to 20 carbon atoms, substituted or unsubstituted alkenyl or alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aromatic ring systems having 6 to 40 aromatic ring atoms, and substituted or unsubstituted heteroaromatic ring systems having 5 to 40 aromatic ring atoms, 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, wherein R.sup.2 is selected from H, D, straight-chain alkyl having 1 to 6 carbon atoms, branched alkyl having 1 to 6 carbon atoms, cyclic alkyl having 3 to 6 carbon atoms, alkenyl or alkynyl groups having 2 to 6 carbon atoms, C.sub.6 to C.sub.18 aryl or C.sub.3 to C.sub.18 heteroaryl.

8. The organic electroluminescent device according to claim 1, wherein the organic hole transport compound of formula (IV) is selected from a compound from F1 to F20: ##STR00128## ##STR00129## ##STR00130## ##STR00131## ##STR00132## ##STR00133##

9. The organic electroluminescent device according to claim 1, wherein the compound of formula (III) is selected from the group of BD1 to BD9: ##STR00134## ##STR00135## ##STR00136##

10. The organic electroluminescent device according to claim 1, wherein the organic emitter host compound is selected from a compound of formula (V): ##STR00137## wherein Ar.sup.41 and Ar.sup.42 are independently selected from substituted or unsubstituted C.sub.6 to C.sub.24 aryl, substituted or unsubstituted C.sub.3 to C.sub.24 heteroaryl; L.sup.41 and L.sup.42 are independently selected from a direct bond or substituted or unsubstituted C.sub.6 to C.sub.24 arylene, substituted or unsubstituted C.sub.3 to C.sub.24 heteroarylene; R.sup.41 to R.sup.48 are independently selected from H, D, substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.19 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl; wherein the substituents on Ar.sup.41, Ar.sup.42, L.sup.41, L.sup.42, R.sup.41 to R.sup.48 are independently selected from D, C.sub.6 to C.sub.10 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, halogen, F or CN.

11. The organic electroluminescent device according to claim 1, wherein the organic emitter host compound of formula (V) is selected from a compound of BH1 to BH13: ##STR00138## ##STR00139## ##STR00140## ##STR00141## ##STR00142##

12. The organic electroluminescent device according to claim 1, wherein light is emitted through the cathode layer.

13. An electronic device comprising the organic electroluminescent device according to claim 1.

14. A display device comprising an organic electroluminescent device according to claim 1.

Description

DESCRIPTION OF THE DRAWINGS

[0592] 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.

[0593] 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.

[0594] FIGS. 1 to 6

[0595] FIG. 1 is a schematic sectional view of an organic electroluminescent device, according to an exemplary embodiment of the present invention;

[0596] FIG. 2 is a schematic sectional view of an organic electroluminescent device, according to an exemplary embodiment of the present invention;

[0597] FIG. 3 is a schematic sectional view of an organic electroluminescent device, according to an exemplary embodiment of the present invention;

[0598] FIG. 4 is a schematic sectional view of an organic electroluminescent device, according to an exemplary embodiment of the present invention;

[0599] FIG. 5 is a schematic sectional view of an organic electroluminescent device, according to an exemplary embodiment of the present invention;

[0600] FIG. 6 is a schematic sectional view of an organic electroluminescent device, according to an exemplary embodiment of the present invention.

[0601] Hereinafter, the figures are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.

[0602] 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.

[0603] FIG. 1 is a schematic sectional view of an organic electroluminescent device 100, according to an exemplary embodiment of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first emission layer (EML) 150, and a cathode layer 190. The HIL 130 is disposed on the anode layer. Onto the HIL 130, the HTL 140, the EML 150, the cathode layer 190 are disposed.

[0604] FIG. 2 is a schematic sectional view of an organic electroluminescent device 100, according to an exemplary embodiment of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first emission layer (EML) 150, an electron transport layer (ETL) 170, and a cathode layer 190. The HIL 130 is disposed on the anode layer. Onto the HIL 130, the HTL 140, the EML 150, the ETL 170 and the cathode layer 190 are disposed.

[0605] FIG. 3 is a schematic sectional view of an organic electroluminescent device 100, according to an exemplary embodiment of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first emission layer (EML) 150, an electron transport layer (ETL) 170, an electron injection layer (EIL) 180 and a cathode layer 190. The HIL 130 is disposed on the anode layer. Onto the HIL 130, the HTL 140, the EML 150, the ETL 170, the EIL 180 and the cathode layer 190 are disposed.

[0606] FIG. 4 is a schematic sectional view of an organic electroluminescent device 100, according to an exemplary embodiment of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, a first emission layer (EML) 150, a hole blocking layer (HBL) 160, an electron transport layer (ETL) 170, an electron injection layer (EIL) 180 and a cathode layer 190. The HIL 130 is disposed on the anode layer. Onto the HIL 130, the HTL 140, the EBL 145, the EML 150, the HBL 160, the ETL 170, the EIL 180 and the cathode layer 190 are disposed.

[0607] FIG. 5 is a schematic sectional view of an organic electroluminescent device 100, according to an exemplary embodiment of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, a first emission layer (EML) 150, a hole blocking layer (HBL) 160, an electron transport layer (ETL) 170, an electron injection layer (EIL) 180, wherein the EIL comprises a first EIL sub-layer (EIL1) 181 and a second EIL sub-layer (EIL2) 182, and a cathode layer 190. The HIL 130 is disposed on the anode layer. Onto the HIL 130, the HTL 140, the EBL 145, the EML 150, the HBL 160, the ETL 170, the EIL 180 and the cathode layer 190 are disposed.

[0608] FIG. 6 is a schematic sectional view of an organic electroluminescent device 100, according to an exemplary embodiment of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode layer 120, wherein the anode layer 120 comprises a first anode sub-layer 121, a second anode sub-layer 122 and a third anode sub-layer 123, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, a first emission layer (EML) 150, a hole blocking layer (HBL) 160, an electron transport layer (ETL) 170, an electron injection layer (EIL) 180, wherein the EIL comprises a first EIL sub-layer (EIL1) 181 and a second EIL sub-layer (EIL2) 182, and a cathode layer 190. The HIL 130 is disposed on the anode layer. Onto the HIL 130, the HTL 140, the EBL 145, the EML 150, the HBL 160, the ETL 170, the EIL 180 and the cathode layer 190 are disposed.

[0609] While not shown in FIG. 1 to FIG. 6, a capping and/or sealing layer may further be formed on the cathode layer 190, in order to seal the organic electroluminescent device 100. In addition, various other modifications may be applied thereto.

[0610] Hereinafter, one or more exemplary embodiments of the present invention will be described in detail with, reference to the following examples. However, these examples are not intended to limit the purpose and scope of the one or more exemplary embodiments of the present invention.

DETAILED DESCRIPTION

[0611] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.

Experimental Data

[0612] Compounds of formula (I), (II), (IIa) to (IId), (AL-I), (III), (IV), (IVa), (IVb) and (V) may be prepared by methods known in the art.

HOMO of Compounds of Formula (III) and (IV)

[0613] The HOMO of compounds of formula (III) and (IV) are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany).

[0614] The optimized geometries and the HOMO and LUMO energy 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 is selected.

[0615] Under these conditions, the HOMO of N2,N2,N2,N2,N7,N7,N7,N7-octakis(4-methoxyphenyl)-9,9-spirobi[fluorene]-2,2,7,7-tetraamine is 4.27 eV.

HOMO and LUMO of the Organic Emitter Host of Formula (V)

[0616] The HOMO and LUMO of the organic emitter host of formula (V) are calculated with the program package ORCA Version 5.0.3-f.1 (Department of theory and spectroscopy, Max Planck Institute fur Kohlenforschung Kaiser Wilhelm Platz 1, 45470 Muelheim/Ruhr, Germany). The optimized geometries and the HOMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase, specifying the deuterium atoms by defining their mass equal to 2.00141amu. If more than one conformation is viable, the conformation with the lowest total energy is selected.

General Procedure for Fabrication of OLEDs

[0617] For all inventive and comparative examples (see Tables 5 and 6), a glass substrate with an anode layer comprising a first anode sub-layer of 120 nm Ag, a second anode sub-layer of 8 nm ITO and a third anode sub-layer of 10 nm ITO was cut to a size of 50 mm50 mm0.7 mm, ultrasonically washed with water for 60 minutes and then with isopropanol for 20 minutes. The liquid film was removed in a nitrogen stream, followed by plasma treatment to prepare the anode layer. The plasma treatment was performed in an atmosphere comprising 97.6 vol.-% nitrogen and 2.4 vol.-% oxygen.

[0618] Then, a hole injection layer was formed on the anode layer in vacuum. In examples 1-1 to 1-12 and comparative examples 1-1 to 1-8, see Table 5, compound of formula (I) is deposited on the anode layer. The thickness of the hole injection layer can be seen in Table 5. In examples 2-1 to 2-6 and comparative examples 2-1 to 2-5, see Table 6, compound of formula (I) and compound of formula (V) are co-deposited on the anode layer to form a hole injection layer having a thickness of 10 nm. The composition of the hole injection layer can be seen in Table 6.

[0619] Then, compound of formula (V) was vacuum deposited on the HIL, to form a first hole transport layer (HTL). The composition and thickness of the HTL can be seen in Tables 5 and 6.

[0620] Then N,N-di([1,1-biphenyl]-4-yl)-3-(9H-carbazol-9-yl)-[1,1-biphenyl]-4-amine (CAS 1464822-27-2) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.

[0621] Then 99 vol.-% 9-(4-(naphthalen-1-yl)phenyl)-10-(phenyl-d5)anthracene (CAS 1185865-32-0) as EML host and 1 vol.-% 2,12-di-tert-butyl-5,9-bis(4-(tert-butyl)phenyl)-7-methyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (CAS 1805802-42-9) as blue EML dopant were deposited on the EBL, to form a first emission layer with a thickness of 20 nm.

[0622] Then a hole blocking layer was formed with a thickness of 5 nm by depositing 2,4-diphenyl-6-(4,5,6-triphenyl-[1,1:2,1:3,1:3,1-quinquephenyl]-3-yl)-1,3,5-triazine (CAS 2032364-64-8) on the first emission layer.

[0623] Then, the electron transport layer having a thickness of 31 nm is formed on the hole blocking layer. The electron transport layer may comprise a composition Comp-1 comprising 30 wt.-% (3-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)phenyl)dimethylphosphine oxide (ETM1) and 70 wt.-% 2-([1,1-biphenyl]-3-yl)-4-phenyl-6-(3-(10-phenylanthracen-9-yl)phenyl)-1,3,5-triazine (ETM2).

[0624] Then the electron injection layer EIL is deposited on the electron transport layer. The EIL comprises a first EIL sub-layer formed of 1 nm LiQ, and a second EIL sub-layer formed of 2 nm Yb.

[0625] Then the cathode layer having a thickness of 13 nm is formed on the electron injection layer by depositing Ag:Mg (90:10 vol.-%) at a rate of 0.01 to 1 A/s at 10.sup.7 mbar.

[0626] Then, N-([1,1-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine was deposited on the cathode layer to form a capping layer with a thickness of 75 nm.

[0627] The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.

[0628] 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 a voltage 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 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m.sup.2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values. The cd/A efficiency at 10 mA/cm.sup.2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.

[0629] In bottom emission devices, the emission is predominately Lambertian and quantified in percent external quantum efficiency (EQE). The light is emitted through the anode layer. To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode at 10 mA/cm.sup.2.

[0630] In top emission devices, the emission is forward directed through the cathode layer, non-Lambertian and also highly dependent on the mirco-cavity. Therefore, the efficiency EQE will be higher compared to bottom emission devices. To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode at 10 mA/cm.sup.2.

[0631] The color space is described by coordinates CIE-x and CIE-y (International Commission on Illumination 1931).

[0632] Lifetime LT of the device is measured at ambient conditions (20 C.) and 30 mA/cm.sup.2, using a Keithley 2400 source meter, and recorded in hours.

[0633] The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.

[0634] To determine the voltage stability overtime U(100 h)-(1 h), a current density of at 30 mA/cm.sup.2 was applied to the device. The operating voltage was measured after 1 hour and after 100 hours, followed by calculation of the voltage stability for the time period of 1 hour to 100 hours. A low value for U(100 h)-(1 h) denotes a low increase in operating voltage over time and thereby improved voltage stability.

Technical Effect of the Invention

[0635] In Table 1 are shown the chemical formulas of a range of compounds of formula (I).

TABLE-US-00001 TABLE 1 Compound of formula (I) and comparative compounds Referred to as: Chemical formula Comparative compound 1 CC-1 [00086] Comparative compound 2 CC-2 [00087] Comparative compound 3 CC-3 [00088] Comparative compound 4 CC-4 [00089] Metal complex 1 MC-1 [00090] Metal complex 2 MC-2 [00091] Metal complex 3 MC-3 [00092] Metal complex 4 MC-4 [00093] Metal complex 5 MC-5 [00094] Metal complex 6 MC-6 [00095]

[0636] In Table 2 are shown the chemical formulas and HOMO values of a range of compounds of formula (IV).

TABLE-US-00002 TABLE 2 Compounds of formula (IV) Referred to as: Chemical formula HOMO (eV) F3 [00096] 4.69 F18 [00097] 4.73 F4 [00098] 4.85 F2 [00099] 4.81

[0637] In Table 3 are shown the chemical formulas and HOMO values of a range of compounds of formula (V).

TABLE-US-00003 TABLE 3 Organic emitter host compound of formula (V) Referred to as: Chemical formula HOMO (eV) BH1 [00100] 5.11 BH2 [00101] 5.11 BH4 [00102] 5.13 BH6 [00103] 5.14 BH8 [00104] 5.12 BH10 [00105] 5.15 BH13 [00106] 5.18

[0638] When the HOMO of BH1 and BH4 are calculated with the same method as for compounds of formula (IV), namely by applying hybrid functional B33LYP with a 6-31G* basis set in the gas phase using program package TURBOMOLE V6.5, as described above, essentially the same values are obtained as shown in Table 3 above.

[0639] In Table 4 are shown values for [HOMO (compound of formula (V))-HOMO (compound of formula (IV)] for a range of compounds of formula (II) and compounds of formula (IV).

TABLE-US-00004 TABLE 4 HOMO (compound of formula (V))- HOMO (compound of formula (IV)) F3 F18 F4 F2 BH1 0.42 0.38 0.26 0.3 BH2 0.42 0.38 0.26 0.3 BH4 0.44 0.4 0.28 0.32 BH6 0.45 0.41 0.29 0.33 BH8 0.43 0.39 0.27 0.31 BH10 0.46 0.42 0.3 0.34 BH13 0.49 0.45 0.33 0.37
In Table 5 are shown performance data of organic electroluminescent devices wherein in the hole injection layer consists of compound of formula (IV).

[0640] In comparative example 1-1, the hole injection layer consists of CuPc. CuPc is free of formula (II), see Table 1. The HOMO (compound of formula (V))-HOMO (compound of formula (IV)) is 0.41 eV. The operating voltage is 8.42 V, the EQE efficiency is 10.6%, the Ceff is 5 cd/A, the lifetime is 1 hour and the voltage stability over time U(100 h)-(1 h) is 2.259 V.

[0641] In comparative example 1-2, the thickness of the hole injection layer is increased to 2 nm. The operating voltage is 10 V. Therefore, the other performance characteristics were not determined.

[0642] In comparative example 1-3, the hole injection layer consists of CC-2. CC-2 is free of formula (II). The operating voltage is improved to 4.15 V. The efficiency is improved to 17.99% EQE and 8.8 cd/A. The lifetime is improved to 18 hours. The voltage stability over time U(100 h)-(1 h) is improved to 0.239 V.

[0643] In comparative example 1-4, the thickness of the hole injection layer is increased to 2 nm. The operating voltage is unchanged, the efficiency is increased to 18.10% EQE and 8.9 cd/A. The lifetime is 9 hours and the voltage stability is 0.313 V.

[0644] In comparative example 1-5, the hole injection layer consists of CC-3. CC-3 is free of formula (II). The operating voltage is improved to 4.05 V. The efficiency is improved to 18.37% EQE and 8.6 cd/A. The lifetime is improved to 13 hours. The voltage stability over time U(100 h)-(1 h) is improved to 0.251 V. In comparative example 1-6, the thickness of the hole injection layer is increased to 2 nm. The performance is essentially the same.

[0645] In examples 1-1 to 1-10, the hole injection layer comprises a range of compounds of formula (I). As can be seen in Table, 3, operating voltage, EQE, Ceff, lifetime and/or voltage stability over time U(100 h)-(1 h) are improved over comparative examples 1-1 to 1-6.

[0646] In comparative example 1-7, the hole injection layer consists of CC-2. CC-2 is free of formula (II). The HOMO (compound of formula (V))-HOMO (compound of formula (IV)) is 0.25 eV. The operating voltage is 4.12 V, the EQE efficiency is 18.47%, the Ceff is 8.9 cd/A, the lifetime is 2 hours and the voltage stability over time U(100 h)-(1 h) is 1.276 V. In comparative example 1-8, the thickness of the hole injection layer is increased to 2 nm. The operating voltage and efficiency are essential unchanged. The lifetime is reduced to 1 hour. The voltage stability over time is improved to 0.722 V.

[0647] In examples 1-11 and 1-12, the hole injection layer comprises MC-1. As can be seen in Table 5, the operating voltage is improved to 3.86 V. The EQE is 17.87 and 18.09%, respectively. The cd/A efficiency is improved to 9.1 and 9.2 cd/A, respectively. The lifetime is improved to 5 and 7 hours, respectively. The voltage stability over time U(100 h)-(1 h) is improved to 0.133 and 0.135 V, respectively.

[0648] In Table 6 are shown performance data for an organic electroluminescent device, wherein the hole injection layer comprises a compound of formula (I) and a compound of formula (IV). The hole injection layer and the first hole transport layer comprise the same compound of formula (IV).

[0649] In comparative example 2-1, the hole injection layer comprises CC-2. CC-2 is free of formula (II). The HOMO (compound of formula (V))-HOMO (compound of formula (IV)) is 0.41 eV. The operating voltage is 4.07 V, the EQE is 18.16%, the Ceff is 8.9 cd/A, the lifetime is 39 hours and the voltage stability over time U(100 h)-(1 h) is 0.251 V.

[0650] In comparative example 2-2, the hole injection layer comprises CC-4. CC-4 is free of formula (II). The operating voltage is 4.27 V, the EQE is 17.37%, the Ceff is 8.2 cd/A, the lifetime is 13 hours and the voltage stability over time U(100 h)-(1 h) is 1.441 V.

[0651] In comparative example 2-3, the hole injection layer comprises CC-3. CC-3 is free of formula (II). The operating voltage is 4.22 V, the EQE is 17.93%, the Ceff is 8.4 cd/A, the lifetime is 17 hours and the voltage stability over time U(100 h)-(1 h) is 1.077 V.

[0652] In example 2-1, the hole injection layer comprises MC-2. The operating voltage is improved to 4.02 V. The efficiency is improved to 18.57% EQE and 8.6 cd/A. The lifetime is high at 38 hours and the voltage stability over time U(100 h)-(1 h) is improved to 0.116 V.

[0653] In examples 2-2 to 2.4, the hole injection layer comprises a range of compounds of formula (I). As can be seen in Table 5, operating voltage, EQE, Ceff, lifetime and/or voltage stability over time U(100 h)-(1 h) are improved over comparative examples 2-1 to 2-3.

[0654] In comparative example 2-4, the hole injection layer comprises CC-2 and compound of formula (IV) F4. CC-2 is free of formula (II). As the HOMO of the compound of formula (IV) is further away from vacuum level, the concentration of CC-2 in the hole injection layer has been increased to 3 mol.-%. The HOMO (compound of formula (V))-HOMO (compound of formula (IV)) is 0.25 eV. The operating voltage is 4.01 V, the efficiency is 18.51% EQE and 8.9 cd/A. The lifetime is 13 hours and the voltage stability over time U(100 h)-(1 h) is 0.764 V.

[0655] In example 2-5, the hole injection layer comprises MC-3. The operating voltage is improved to 3.86 V, the efficiency is 17.94% EQE and 9 cd/A. The lifetime is 27 hours and the voltage stability over time U(100 h)-(1 h) is improved to 0.133 V.

[0656] In comparative example 2-5, the hole injection layer comprises CC-2 and compound of formula (IV) F2. CC-2 is free of formula (II). The HOMO (compound of formula (V))-HOMO (compound of formula (IV)) is 0.29 eV. The operating voltage is 3.90 V, the efficiency is 15.71% EQE and 8.0 cd/A. The lifetime is 55 hours and the voltage stability over time U(100 h)-(1 h) is 0.212 V.

[0657] In example 2-6, the hole injection layer comprises MC-3. The operating voltage is improved to 3.79 V, the efficiency is 15.68% EQE and 7.9 cd/A. The lifetime is 55 hours and the voltage stability over time U(100 h)-(1 h) is improved to 0.170 V.

[0658] In summary, an improvement in operating voltage, EQE, cd/A efficiency, lifetime and/or voltage stability over time U(100 h)-(1 h) has been obtained.

[0659] An improvement in operating voltage, EQE and cd/A efficiency may result in lower power consumption of organic electroluminescent devices, in particular mobile devices.

[0660] An improvement in lifetime and/or voltage stability over time may lead to improved stability over time of organic electroluminescent devices.

TABLE-US-00005 TABLE 5 Performance of an organic electroluminescent device wherein the hole injection layer consists of a compound of formula (I) HOMO (compound of Compound of formula (V)) U(100 formula (I) or Compound HOMO LT at h) (1 comparative of formula (compound Thickness 30 h) at 30 compound Thickness (IV) in the of formula first HTL Voltage EQE CEff mA/cm.sup.2 mA/cm.sup.2 in the HIL HIL [nm] first HTL (IV)) [eV] [nm] [V] [%] [cd/A] [h] [V] Comparative CuPc 1 F3 0.41 131 8.42 10.60 5.0 1 2.259 example 1-1 Comparative CuPc 2 F3 0.41 131 >10 n.d. .sup.1 n.d. n.d. n.d. example 1-2 Comparative CC-2 1 F3 0.41 131 4.15 17.99 8.8 18 0.239 example 1-3 Comparative CC-2 2 F3 0.41 131 4.15 18.10 8.9 9 0.313 example 1-4 Comparative CC-3 1 F3 0.41 131 4.05 18.37 8.6 13 0.251 example 1-5 Comparative CC-3 2 F3 0.41 131 4.02 18.49 8.8 10 0.215 example 1-6 Example 1-1 MC-1 1 F3 0.41 131 4.06 18.40 8.8 9 0.096 Example 1-2 MC-1 2 F3 0.41 131 4.02 18.66 8.8 12 0.100 Example 1-3 MC-2 1 F3 0.41 131 4.03 18.67 8.7 19 0.089 Example 1-4 MC-2 2 F3 0.41 131 4.00 18.86 8.6 23 0.105 Example 1-5 MC-5 1 F3 0.41 131 4.02 18.62 8.7 37 0.072 Example 1-6 MC-5 2 F3 0.41 131 3.99 18.80 8.6 34 0.057 Example 1-7 MC-4 1 F3 0.41 131 4.10 18.44 8.7 42 0.079 Example 1-8 MC-4 2 F3 0.41 131 4.02 18.63 8.8 41 0.064 Example 1-9 MC-6 1 F3 0.41 131 4.03 18.25 8.7 38 0.054 Example 1-10 MC-6 2 F3 0.41 131 3.97 18.30 8.7 38 0.059 Comparative CC-2 1 F4 0.25 137 4.12 18.47 8.9 2 1.276 example 1-7 Comparative CC-2 2 F4 0.25 137 4.13 18.43 8.9 1 0.722 example 1-8 Example 1-11 MC-1 1 F4 0.25 137 3.86 17.87 9.1 5 0.133 Example 1-12 MC-1 2 F4 0.25 137 3.86 18.09 9.2 7 0.135 .sup.1 n.d. = not determined

TABLE-US-00006 TABLE 6 Performance of an organic electroluminescent device wherein the hole injection layer comprises a compound of formula (I) and a compound of formula (IV) Concentration HOMO of compound (compound Compound of formula of formula of formula (I) or (V)) U(100 (I) or Compound comparative Compound HOMO LT at h) (1 comparative of formula compound in of formula Thickness (compound 30 h) at 30 compound (IV) in the HIL (IV) in the first HTL of formula Voltage EQE CEff mA/cm.sup.2 mA/cm.sup.2 in the HIL the HIL [mol.-%] first HTL [nm] (IV)) [eV] [V] [%] [cd/A] [h] [V] Comparative CC-2 F3 1 F3 123 0.41 4.07 18.16 8.9 39 0.251 example 2-1 Comparative CC-4 F3 1 F3 123 0.41 4.27 17.37 8.2 13 1.441 example 2-2 Comparative CC-3 F3 1 F3 123 0.41 4.22 17.93 8.4 17 1.077 example 2-3 Example 2-1 MC-2 F3 1 F3 123 0.41 4.02 18.57 8.6 38 0.116 Example 2-2 MC-1 F3 1 F3 123 0.41 4.06 18.17 8.6 35 0.157 Example 2-3 MC-3 F3 1 F3 123 0.41 3.96 18.43 8.7 36 0.117 Example 2-4 MC-6 F3 1 F3 123 0.41 3.94 18.42 8.8 42 0.061 Comparative CC-2 F4 3 F4 129 0.25 4.01 18.51 8.9 13 0.764 example 2-4 Example 2-5 MC-3 F4 3 F4 129 0.25 3.86 17.94 9.0 27 0.133 Comparative CC-2 F2 3 F2 124 0.29 3.90 15.71 8.0 55 0.212 example 2-5 Example 2-6 MC-3 F2 3 F2 124 0.29 3.79 15.68 7.9 55 0.170

[0661] 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.