Organic electroluminescent device

1. An organic electroluminescent device comprising, in this sequence:

anode, phosphorescent emitter layer 1 , phosphorescent emitter layer 2 , which is in direct contact with said phosphorescent emitter layer 1 , a charge-generation layer, blue-emitting layer, and cathode, wherein said phosphorescent emitter layer 1 comprises a hole-conducting matrix material and two different phosphorescent emitters wherein one phosphorescent emitter is a shorter-wave phosphorescent emitter and one phosphorescent emitter is a longer-wave phosphorescent emitter, and said phosphorescent emitter layer 2 comprises an electron-conducting matrix material and a phosphorescent emitter, wherein the phosphorescent emitter of emitter layer 2 has the same emission maximum as the shorter-wave phosphorescent emitter of emitter layer 1 , wherein said device is a white-emitting, tandem organic electroluminescent device.

2. The organic electroluminescent device of claim 1 , wherein the phosphorescent emitter of emitter layer 2 is identical to the shorter-wave phosphorescent emitter of emitter layer 1 .

3. The organic electroluminescent device of claim 1 , wherein said phosphorescent emitter layer 1 is a yellow-, orange-, or red-emitting layer and phosphorescent emitter layer 2 is a green- or yellow-emitting layer.

4. The organic electroluminescent device of claim 1 , wherein said phosphorescent emitter layer 1 and said phosphorescent emitter layer 2 emit in total light having color coordinates of 0.45 ≦CIE x≦0.58.

5. The organic electroluminescent device of claim 1 , wherein said hole-conducting matrix material in said phosphorescent emitter layer 1 is a material which has an HOMO of ≧−5.5 eV.

6. The organic electroluminescent device of claim 1 , wherein the triplet energy T 1 of the hole-conducting matrix material in said phosphorescent emitter layer 1 is greater than that of the longer-wave emitter.

7. The organic electroluminescent device of claim 1 , wherein the electron-conducting matrix material in said phosphorescent emitter layer 2 is a material whose LUMO is in the range from −2.3 eV to −3.1 eV.

8. The organic electroluminescent device of claim 1 , wherein said phosphorescent emitter layer 2 comprises a mixture of an electron-conducting matrix material and at least one further matrix material.

9. The organic electroluminescent device of claim 1 , wherein the triplet energy T 1 of the electron-conducting matrix material in said phosphorescent emitter layer 2 is ≧2.5 eV.

10. The organic electroluminescent device of claim 1 , wherein the shorter-wave phosphorescent emitter is present in said phosphorescent emitter layer 1 in a concentration of 3 to 25% by vol. and the longer-wave phosphorescent emitter is present in emitter layer 1 in a concentration of 2 to 15% by vol., and wherein the phosphorescent emitter is present in said phosphorescent emitter layer 2 in a concentration of 2 to 20% by vol.

11. The organic electroluminescent device of claim 1 , wherein the electron-conducting matrix material in said phosphorescent emitter layer 2 is selected from the group consisting of compounds of the formulae (1) to (5),

wherein:

Ar 1 is, identically or differently on each occurrence, a monovalent aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 1 ;

Ar 2 is a divalent aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 1 ;

R 1 is, identically or differently on each occurrence, H; D; F; Cl; Br; I; CHO; C(═O)Ar 3 ; P(═O)(Ar 3 ) 2 ; S(═O)Ar 3 ; S(═O) 2 Ar 3 ; CR 2 ═CR 2 Ar 3 ; CN; NO 2 ; Si(R 2 ) 3 ; B(OR 2 ) 2 ; B(R 2 ) 2 ; B(N(R 2 ) 2 ) 2 ; OSO 2 R 2 ; a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms, a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms, a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which are optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups are optionally replaced by R 2 C═CR 2 , C═C , Si(R 2 ) 2 , Ge(R 2 ) 2 , Sn(R 2 ) 2 , C═O, C═S, C═Se, C═NR 2 , P(═O)(R 2 ), SO, SO 2 , NR 2 , O, S, or CONR 2 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO 2 ; an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or a combination of these systems; wherein two or more adjacent substituents R 1 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system;

Ar 3 is, identically or differently on each occurrence, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, optionally substituted by one or more radicals R 2 ;

R 2 is, identically or differently on each occurrence, H, D, CN, or an aliphatic, aromatic and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by D or F, wherein two or more adjacent substituents R 2 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system;

or wherein the electron-conducting matrix material in said phosphorescent emitter layer 2 is a compound of formula (21),

wherein:

Ar is, identically or differently on each occurrence, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more groups R 1 ; and

R 1 is, identically or differently on each occurrence, H; D; F; Cl; Br; I; CHO; C(═O)Ar 3 ; P(═O)(Ar 3 ) 2 ; S(═O)Ar 3 ; S(═O) 2 Ar 3 ; CR 2 ═CR 2 Ar 3 ; CN; NO 2 ; Si(R 2 ) 3 ; B(OR 2 ) 2 ; B(R 2 ) 2 ; B(N(R 2 ) 2 ) 2 ; OSO 2 R 2 ; a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms, a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms, a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which are optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups are optionally replaced by R 2 C═CR 2 , C≡C , Si(R 2 ) 2 , Ge(R 2 ) 2 , Sn(R 2 ) 2 , C═O, C═S, C═Se, C═NR 2 , P(═O)(R 2 ), SO, SO 2 , NR 2 , O, S, or CONR 2 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO 2 ; an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or a combination of these systems; wherein two or more adjacent substituents R 1 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system.

12. The organic electroluminescent device of claim 1 , wherein the hole-conducting matrix material in said phosphorescent emitter layer 1 is selected from the group consisting of the compounds of formulae (26) to (32),

wherein:

Ar 4 is, identically or differently on each occurrence, a divalent, trivalent or tetravalent aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 1 ;

Ar 5 is, identically or differently on each occurrence, a monovalent aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 1 , wherein two groups Ar 5 which are bonded to the same nitrogen atom or a group Ar 4 with a group Ar 5 which are bonded to the same nitrogen atom are optionally linked to one another by a single bond or a bridge selected from the group consisting of B(R 1 ), C(R 1 ) 2 , Si(R 1 ) 2 , C═O, C═NR 1 , C═C(R 1 ) 2 , O, S, S═O, SO 2 , N(R 1 ), P(R 1 ), and P(═O)R 1 ; and

R 1 is, identically or differently on each occurrence, H; D; F; Cl; Br; I; CHO; C(═O)Ar 3 ; P(═O)(Ar 3 ) 2 ; S(═O)Ar 3 ; S(═O) 2 Ar 3 ; CR 2 ═CR 2 Ar 3 ; CN; NO 2 ; Si(R 2 ) 3 ; B(OR 2 ) 2 ; B(R 2 ) 2 ; B(N(R 2 ) 2 ) 2 ; OSO 2 R 2 ; a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms, a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms, a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which are optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups are optionally replaced by R 2 C═CR 2 , C≡C , Si(R 2 ) 2 , Ge(R 2 ) 2 , Sn(R 2 ) 2 , C═O, C═S, C═Se, C═NR 2 , P(═O)(R 2 ), SO, SO 2 , NR 2 , O, S, or CONR 2 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO 2 ; an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or a combination of these systems; wherein two or more adjacent substituents R 1 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system;

or the hole-conducting matrix material in said phosphorescent emitter layer 1 is selected from the group consisting of the compounds of formulae (33) and (34),

wherein Ar 5 and R 1 are defined as above.

13. The organic electroluminescent device of claim 1 , wherein a phosphorescent compound of the formulae (35) to (38) is present in the phosphorescent emitter layer 1 or the phosphorescent emitter layer 2 ,

wherein:

DCy is, identically or differently on each occurrence, a cyclic group which contains at least one donor atom, carbon in the form of a carbene or phosphorus, via which the cyclic group is bonded to the metal, and which optionally carries one or more substituents R 1 , wherein the groups DCy and CCy are connected to one another via a covalent bond;

CCy is, identically or differently on each occurrence, a cyclic group which contains a carbon atom via which the cyclic group is bonded to the metal and which optionally carries one or more substituents R 1 ;

A is, identically or differently on each occurrence, a monoanionic, bidentate-chelating ligand; and

R 1 is, identically or differently on each occurrence, H; D; F; Cl; Br; I; CHO;

C(═O)Ar 3 ; P(═O)(Ar 3 ) 2 ; S(═O)Ar 3 ; S(═O) 2 Ar 3 ; CR 2 ═CR 2 Ar 3 ; CN; NO 2 ; Si(R 2 ) 3 ; B(OR 2 ) 2 ; B(R 2 ) 2 ; B(N(R 2 ) 2 ) 2 ; OSO 2 R 2 ; a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms, a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms, a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which are optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups are optionally replaced by R 2 C═CR 2 , C≡C , Si(R 2 ) 2 , Ge(R 2 ) 2 , Sn(R 2 ) 2 , C═O, C═S, C═Se, C═NR 2 , P(═O)(R 2 ), SO, SO 2 , NR 2 , O, S, or CONR 2 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO 2 ; an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, optionally substituted by one or more radicals R 2 ; or a combination of these systems; wherein two or more adjacent substituents R 1 optionally define a mono- or polycyclic, aliphatic, or aromatic ring system.

14. The organic electroluminescent device of claim 1 , wherein the charge-generation layer is formed by coupling an n-conducting layer and a p-conducting layer to one another, where the p-conducting layer comprises p-doped organic hole-transport materials or comprises inorganic materials, and the n-conducting layer is a doped organic electron-transport layer.

15. A process for the production of the organic electroluminescent device of claim 1 , wherein one or more layers are produced by means of a sublimation process or by means of the organic vapour-phase deposition process or with the aid of carrier-gas sublimation or from solution or by means of a printing process.

16. The organic electroluminescent device of claim 5 , wherein said hole-conducting matrix material in said phosphorescent emitter layer 1 is a material which has an HOMO of ≧−5.3 eV.

17. The organic electroluminescent device of claim 7 , wherein the electron-conducting matrix material in emitter layer 2 is a material whose LUMO is in the range from −2.6 eV to −2.9 eV.

18. The organic electroluminescent device of claim 9 , wherein the triplet energy T 1 of the electron-conducting matrix material in said phosphorescent emitter layer 2 is ≧2.7 eV.

19. The organic electroluminescent device of claim 13 , wherein A is a diketonate ligand.