Organic electroluminescent device comprising anode, cathode and at least one emission layer comprising at least one matrix material A which is doped with at least one phosphorescent emitter, where the phosphorescent emitter contains iridium, and at least one hole-blocking layer comprising at least one hole-blocking material B, characterised in that the hole-blocking material B contains at least one chemical structural unit of the formula Y=X, where the hole-blocking material B has the formula or according to Scheme 1 where the symbols used have the following meaning: Y is C or P; X is O; R 1, R 2, R 3 are on each occurrence, identically or differently, H, F, CN, N(R 4) 2, a straight-chain, branched or cyclic alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms, which may be substituted by R 5 or also unsubstituted, in which one or more non-adjacent CH 2 groups may be replaced by -R 6 C=CR 6 -, -C≡C-, Si(R 6) 2, Ge(R 6) 2, Sn(R 6) 2, C=O, C=S, C=Se, C=NR 6, -O-, -S-, -NR 6 - or -CONR 6 - and in which one or more H atoms may be replaced by F, Cl, Br, I, CN or NO 2, or an aromatic or heteroaromatic ring system or an aryloxy or heteroaryloxy group having 1 to 40 aromatic C atoms, which may be substituted by one or more radicals R 5; a plurality of substituents R 1, R 2 and/or R 3 may form a mono- or polycyclic, aliphatic or aromatic ring system with one another; or an aromatic or heteroaromatic ring system bonded via a divalent group -Z-, or an aryloxy or heteroaryloxy group, in each case having 1 to 40 aromatic C atoms, in which one or more H atoms may be replaced by F, Cl, Br or I or which may be substituted by one or more non-aromatic radicals R 4, where a plurality of substituents R 4 may form a further mono- or polycyclic, aliphatic or aromatic ring system; R 4 is on each occurrence, identically or differently, a straight-chain, branched or cyclic alkyl or alkoxy chain having 1 to 22 C atoms, in which, in addition, one or more non-adjacent C atoms may be replaced by -R 6 C=CR 6 -, -C≡C-, Si(R 6) 2, Ge(R 6) 2, Sn(R 6) 2, -NR 6 -, -O-, -S-, -CO-O- or -O-CO-O- and in which one or more H atoms may be replaced by fluorine, an aryl, heteroaryl or aryloxy group having 1 to 40 C atoms, which may also be substituted by one or more radicals R 6, or OH or N(R 5) 2; R 5 is on each occurrence, identically or differently, R 4 or CN, B(R 6) 2 or Si(R 6) 3; R 6 is on each occurrence, identically or differently, H or an aliphatic or aromatic hydrocarbon radical having 1 to 20 C atoms; Z is a straight-chain, branched or cyclic, preferably conjugated radical having 1 to 40 C atoms, which is preferably in conjugation with the two other substituents, where the number of atoms of Z that link the group of the formula and the aromatic radical is preferably an even number, where one or more non-adjacent C atoms may be replaced by -O-, -S- or -NR 1 - and one or more C atoms may be substituted by a radical R 1 or halogen; and with the proviso that the molecular weight of the hole-blocking material B is greater than 150 g/mol and with the proviso that the matrix material A is not identical with the hole-blocking material B. Y is C or P; X is O; R 1, R 2, R 3 are on each occurrence, identically or differently, H, F, CN, N(R 4) 2, a straight-chain, branched or cyclic alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms, which may be substituted by R 5 or also unsubstituted, in which one or more non-adjacent CH 2 groups may be replaced by -R 6 C=CR 6 -, -C≡C-, Si(R 6) 2, Ge(R 6) 2, Sn(R 6) 2, C=O, C=S, C=Se, C=NR 6, -O-, -S-, -NR 6 - or -CONR 6 - and in which one or more H atoms may be replaced by F, Cl, Br, I, CN or NO 2, or an aromatic or heteroaromatic ring system or an aryloxy or heteroaryloxy group having 1 to 40 aromatic C atoms, which may be substituted by one or more radicals R 5; a plurality of substituents R 1, R 2 and/or R 3 may form a mono- or polycyclic, aliphatic or aromatic ring system with one another; or an aromatic or heteroaromatic ring system bonded via a divalent group -Z-, or an aryloxy or heteroaryloxy group, in each case having 1 to 40 aromatic C atoms, in which one or more H atoms may be replaced by F, Cl, Br or I or which may be substituted by one or more non-aromatic radicals R 4, where a plurality of substituents R 4 may form a further mono- or polycyclic, aliphatic or aromatic ring system; R 4 is on each occurrence, identically or differently, a straight-chain, branched or cyclic alkyl or alkoxy chain having 1 to 22 C atoms, in which, in addition, one or more non-adjacent C atoms may be replaced by -R 6 C=CR 6 -, -C≡C-, Si(R 6) 2, Ge(R 6) 2, Sn(R 6) 2, -NR 6 -, -O-, -S-, -CO-O- or -O-CO-O- and in which one or more H atoms may be replaced by fluorine, an aryl, heteroaryl or aryloxy group having 1 to 40 C atoms, which may also be substituted by one or more radicals R 6, or OH or N(R 5) 2; R 5 is on each occurrence, identically or differently, R 4 or CN, B(R 6) 2 or Si(R 6) 3; R 6 is on each occurrence, identically or differently, H or an aliphatic or aromatic hydrocarbon radical having 1 to 20 C atoms; Z is a straight-chain, branched or cyclic, preferably conjugated radical having 1 to 40 C atoms, which is preferably in conjugation with the two other substituents, where the number of atoms of Z that link the group of the formula and the aromatic radical is preferably an even number, where one or more non-adjacent C atoms may be replaced by -O-, -S- or -NR 1 - and one or more C atoms may be substituted by a radical R 1 or halogen;