Organic electroluminescent device

An organic electroluminescent device comprising an anode, a cathode and at least one emitting layer which comprises at least one phosphorescent compound which is doped into a mixture of two materials A and B, where materials A and B are defined low-molecular-weight compounds having a molecular weight of 2000 g/mol or less, wherein material A is a charge-transporting material and is an electron-conducting compound which is selected from the group consisting of aromatic ketones, aromatic phosphine oxides, aromatic sulfoxides, aromatic sulfones, triazine derivatives, zinc complexes and aluminum complexes,

• and in that material B which is not involved in charge transport, has a HOMO of −5.4 eV or less and a LUMO of −2.4 eV or more and which has an energy gap of at least 3.5 eV and wherein the material B is a compound of the formula (23), (24) or (25):
• wherein
• Ar is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which optionally in each case be substituted by one or more groups R1;
• R1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, C(═O)Ar1, P(═O)(Ar1)2, S(═O)Ar1, S(═O)2Ar1, CR2═CR2Ar1, CN, NO2, Si(R2)3, B(OR2)2, B(R2)2, B(N(R2)2)2, OSO2R2, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a straight-chain alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkenyl, alkynyl, alkoxy or thioalkoxy group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, where one or more non-adjacent CH2 groups is optionally replaced by R2C═CR2, C≡C, Si(R2)2, Ge(R2)2, Sn(R2)2, C═O, C═S, C═Se, C═NR2, P(═O)(R2), SO, SO2, NR2, O, S or CONR2 and where one or more H atoms is optionally replaced by F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is optionally in each case be substituted by one or more radicals R2, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R2, or a combination of these systems;
• two or more adjacent substituents R1 here optionally forms a mono- or polycyclic, aliphatic or aromatic ring system with one another;
• Ar1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R2;
• R2 is on each occurrence, identically or differently, H, D, CN or an aliphatic, aromatic and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, in which, in addition, H atoms is optionally replaced by F;
• two or more adjacent substituents R2 here optionally forms a mono- or polycyclic, aliphatic or aromatic ring system with one another,
• n is, identically or differently on each occurrence, 0 or 1,
• R3 is on each occurrence, identically or differently, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, or an aromatic ring system having 6 to 60 aromatic C atoms, which does not contain any non-aromatic groups other than carbon or hydrogen and which is optionally substituted by one or more radicals R4;
• two or more radicals R3 here optionally forms a ring system with one another;
• R4 is on each occurrence, identically or differently, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms;
• two or more radicals R4 here optionally forms a ring system with one another;
• q is 1, 2, 3 or 4.