Organic electroluminescent device

An organic electroluminescent device comprising:

• an anode;
• a cathode;
• at least one blue light-emitting layer arranged between the cathode and the anode;
• and
• at least one hole-transport layer arranged between the anode and the at least one blue light-emitting layer;
• wherein the at least one blue light-emitting layer comprises an elongated bis-indenofluorene derivative, and
• wherein the at least one hole-transport layer comprises a polymer with non-conjugated units and
• wherein the elongated bis-indenofluorene derivative is a compound of formula (1):
• wherein
• Ar1 is identically or differently on each occurrence an aryl or heteroaryl group having 6 to 18 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R1, wherein at least one group Ar1 in formula (1) has 10 or more aromatic ring atoms;
• Ar2 is identically or differently on each occurrence an aryl or heteroaryl group having 6 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R1;
• Ar3 and Ar4
• are identically or differently on each occurrence an aromatic or heteroaromatic ring system having 5 to 25 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R1;
• E is identically or differently on each occurrence selected from the group consisting of —BR0—, —C(R0)2—, —C(R0)2—C(R0)2—, —C(R0)2—O—, —C(R0)2—S—, —R0C═CR0—, —R0C═N—, —Si(R0)2—, —Si(R0)2—Si(R0)2—, —C(═O)—, —C(═NR0)—, —C(═C(R0)2)—, —O—, —S—, —S(═O)—, —SO2—, —N(R0)—, —P(R0)— and —((═O)R0)—, and two groups E are optionally in a cis- or trans-position relative to each other;
• R0 and R1
• are identically or differently on each occurrence H, D, F, Cl, Br, I, CHO, CN, N(Ar5)2, C(═O)Ar5, P(═O)(Ar5)2, S(═O)Ar5, S(═O)2Ar5, NO2, Si(R2)3, B(OR2)2, OSO2R2, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 40 C atoms or a branched or a cyclic alkyl, alkoxy, or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, wherein in each case 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, P(═O)(R2), SO, SO2, O, S or CONR2 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO2, an aromatic or hetero-aromatic ring system having 5 to 60 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R2, or an aryloxy group having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R2, and wherein two adjacent substituents R0 and/or two adjacent substituents R1 optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R2;
• R2 is identically or differently on each occurrence H, D, F, Cl, Br, I, CHO, CN, N(Ar5)2, C(═O)Ar5, P(═O)(Ar5)2, S(═O)Ar5, S(═O)2Ar5, NO2, Si(R3)3, B(OR3)2, OSO2R3, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R3, wherein in each case one or more non-adjacent CH2 groups are optionally replaced by R3C═CR3, C≡C, Si(R3)2, Ge(R3)2, Sn(R3)2, C═O, C═S, C═Se, P(═O)(R3), SO, SO2, O, S, or CONR3 and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO2, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R3, or an aryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals R3, and wherein two adjacent substituents R2 optionally define a mono- or polycyclic, aliphatic ring system or aromatic ring system, which is optionally substituted by one or more radicals R3;
• R3 is identically or differently on each occurrence H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy, or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkyl group having 3 to 20 C atoms, wherein in each case one or more non-adjacent CH2 groups are optionally replaced by SO, SO2, O, or S and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms;
• Ar5 is an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which in each case also optionally substituted by one or more radicals R3;
• n is an integer from 1 to 20;
• wherein if n is equal to 1 and at least one of group Ar3 or group Ar4 is a phenyl group, then the compound of formula (1) bears at least one group R0 or R1, which is a straight-chain alkyl group having 2 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R2, and
• wherein the at least one non-conjugated polymer is a polymer comprising at least one structural unit of formula (I):
• wherein
• Ar1, Ar2, Ar3, Ar4, and Ar5
• are identically or differently selected from the group consisting of heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R1, and aromatic ring systems having 6 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R1;
• with the proviso that at least one of groups Ar2 and Ar4 is in each case substituted by a group R4 in at least one position ortho to the bond to N, wherein the group R4 optionally defines a ring with the corresponding group Ar2 or Ar4 to which it is bonded, and wherein R4 is bonded to a group selected from the group consisting of groups Ar2 and Ar4 directly or via a linker group X;
• R1 is identically or differently on each occurrence selected from the group consisting of H, D, F, C(═O)R2, CN, Si(R2)3, N(R2)2, P(═O)(R2)2, OR2, S(═O)R2, S(═O)2R2, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• wherein two or more radicals R1 are optionally linked to one another and optionally define a ring;
• wherein the alkyl, alkoxy, alkenyl, and alkynyl groups and the aromatic ring systems and heteroaromatic ring systems are in each case optionally substituted by one or more radicals R2, and wherein one or more CH2 groups in the alkyl, alkoxy, alkenyl, and alkynyl groups are optionally replaced by —R2C═CR2—, —C≡C—, Si(R2)2, C═O, C═NR2, —C(═O)O—, —C(═O)NR2—, NR2, P(═O)(R2), —O—, —S—, SO, or SO2;
• R2 is identically or differently on each occurrence selected from the group consisting of H, D, F, C(═O)R3, CN, Si(R3)3, N(R3)2, P(═O)(R3)2, OR3, S(═O)R3, S(═O)2R3, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched, or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• wherein two or more radicals R1 or R2 are optionally linked to one another and optionally define a ring;
• wherein the alkyl, alkoxy, alkenyl, and alkynyl groups and the aromatic ring systems and heteroaromatic ring systems are in each case optionally substituted by one or more radicals R3;
• and wherein one or more CH2 groups in the alkyl, alkoxy, alkenyl, and alkynyl groups are optionally replaced by —R3C═CR3—, —C≡C—, Si(R3)2, C═O, C═NR3, —C(═O)O—, —C(═O)NR3—, NR3, P(═O)(R3), —O—, —S—, SO, or SO2;
• R3 is identically or differently on each occurrence selected from the group consisting of H, D, F, CN, alkyl, or alkoxy groups having 1 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• wherein two or more radicals R3 are optionally linked to one another and optionally define a ring;
• and wherein the alkyl, alkoxy, alkenyl, and alkynyl groups, aromatic ring systems, and heteroaromatic ring systems are optionally substituted by F or CN;
• R4 is identically or differently on each occurrence selected from the group consisting of heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R2, and aromatic ring systems having 6 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R2;
• X is identically or differently on each occurrence selected from the group consisting of C(R2)2, Si(R2)2, NR2, O, S, and C═O;
• n is equal to 0 or 1;
• and at least one structural unit selected from the group consisting of:
• structural units A, consisting of a planar aromatic group selected from the group consisting of aryl groups having 6 to 40 aromatic ring atoms and heteroaryl groups having 6 to 40 aromatic ring atoms, wherein the planar aromatic group has at least one radical R5 which, owing to its space requirement, causes a rotation of the planar aromatic group relative to the plane formed by the planar aromatic groups of the directly adjacent structural units, and wherein the above-mentioned aryl groups and heteroaryl groups are in each case optionally substituted by one or more further radicals R5;
• structural units B which comprise two groups, connected directly to one another, selected from the group consisting of aryl groups having 6 to 40 aromatic ring atoms, which are in each case optionally substituted by one or more radicals R5, and heteroaryl groups having 5 to 40 aromatic ring atoms, which are in each case optionally substituted by one or more radicals R5, wherein the plane of conjugation of the second aryl or heteroaryl group is rotated relative to the plane of conjugation of the first aryl or heteroaryl group about the axis of the bond between the two groups;
• and
• structural units C of formula (II-C):
• wherein
• Ar6 and Ar7
• are identically or differently on each occurrence selected from the group consisting of aromatic ring systems having 6 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R5, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R5;
• R5 is identically or differently on each occurrence selected from the group consisting of H, D, F, C(═O)R2, CN, Si(R2)3, N(R2)2, P(═O)(R2)2, OR2, S(═O)R2, S(═O)2R2, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms;
• wherein two or more radicals R1 are optionally linked to one another and optionally define a ring;
• wherein the alkyl, alkoxy, alkenyl, and alkynyl groups and the aromatic ring systems and heteroaromatic ring systems are in each case optionally substituted by one or more radicals R2;
• and wherein one or more CH2 groups in the alkyl, alkoxy, alkenyl, and alkynyl groups are optionally replaced by —R2C═CR2—, —C≡C—, Si(R2)2, C═O, C═NR2, —C(═O)O—, —C(═O)NR2—, NR2, P(═O)(R2), —O—, —S—, SO, or SO2;
• k has a value of 0 to 9;
• wherein one or more CH2 units in the alkylene chain of formula (II-C) are optionally replaced by a divalent unit selected from the group consisting of C═O, ═NR5, —C(═O)O—, —C(═O)NR5—, Si(R5)2, NR5, P(═O)(R5), O, S, SO, and SO2;
• and
• wherein one or more H atoms in the alkylene chain of formula (II-C) are in each case optionally replaced by a radical R5.