NOVELTY - Substituted carbazole compounds (Q) are new.    USE - (Q) or their oligomers, polymers or dendrimers are useful: in an electronic device comprising organic integrated circuits, organic field-effect transistors, organic thin film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes or organic light emitting diodes; and as a matrix material in an emitting layer and/or as a hole transport material in a hole transport layer and/or as electron transport material in an electron transport layer (all claimed).    ADVANTAGE - (Q) have high stability, and provide electronic devices with improved efficiency, operation voltage and service life.    DETAILED DESCRIPTION - Substituted carbazole compounds (Q) of formulae (I) and (II) are new.    Y1 = BR1, C(R1)2, C=O, C=NR1, C=C(R1)2, C=S, Si(R1)2, NR1, PR1, P(=O)R1, O, S, S=O or S(=O)2;    L = single bond (when p is 2) or 1-20C-alkylene, 2-20C-alkenylene or 2-20C-alkynylene (where one or more CH2 groups are optionally replaced by Si(R1)2, O, S, C=O, C=NR1, C(=O)O, (C=O)NR1, NR1, P(=O)(R1), SO or SO2 and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), 5-60 membered (hetero)aryl (optionally substituted by one or more R1), C=O, C=NR1, Si(R1)2, NR1, P(=O)(R1), O, S, SO or SO2; either    R1 = linear 1-20C-(thio)alkyl or -alkoxy or a branched or cyclic 3-20C-(thio)alkyl or -alkoxy or 2-20C-alkenyl or -alkynyl (all optionally substituted with one or more R2, where one or more adjacent or non-adjacent CH2-groups are optionally replaced by -R2C=CR2-, -CC-, Si(R2)2, Ge(R2)2, Sn(R2)2, C=O, C=S, C=Se, C=NR2, -C(=O)O-, -C(=O)NR2-, NR2, P(=O)(R2), -O-, -S-, SO or SO2 and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), 5-60 membered (hetero)aryl (optionally substituted with one or more R2), H, D, F, Cl, Br, I, B(OR2)2, CHO, C(=O)R2, CR2=C(R2)2, CN, C(=O)OR2, C(=O)N(R2)2, Si(R2)3, N(R2)2, NO2, P(=O)(R2)2, OSO2R2, OR2, S(=O)R2 or S(=O)2R2; or    two or more R1 linked together = ring or ring system;    R2 = linear 1-20C-(thio)alkyl or -alkoxy or a branched or cyclic 3-20C-(thio)alkyl or -alkoxy or 2-20C-alkenyl or -alkynyl (all optionally substituted with one or more R3, where one or more adjacent or non-adjacent CH2-groups are optionally replaced by -R3C=CR3-, -CC-, Si(R3)2, Ge(R3)2, Sn(R3)2, C=O, C=S, C=Se, C=NR3, -C(=O)O-, -C(=O)NR3-, NR3, P(=O)(R3), -O-, -S-, SO or SO2 and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), or 5-60 membered-(hetero)aryl or (hetero)aryloxy (both optionally substituted with one or more R3), H, D, F, Cl, Br, I, B(OR3)2, CHO, C(=O)R3, CR3=C(R3)2, CN, C(=O)OR3, C(=O)N(R3)2, Si(R3)3, N(R3)2, NO2, P(=O)(R3)2, OSO2R3, OR3, S(=O)R3 or S(=O)2R3; or    two or more R2 linked together = ring or ring system; either    R3 = 1-20C-aliphatic or (hetero)aromatic organic radical (where one or more H atoms are optionally replaced by D or F), H, D or F; or    two or more R3 linked together = ring or ring system;    a1 = point of attachment, in which a benzene ring is optionally fused;    n = 0 or 1; and    p = 2-6.    Where: Y1 and the nitrogen atom in the vicinal positions bind the six-membered ring of (Q); in (Q) further none or 1-6 carbon atoms, which are part of (hetero)aromatic rings are optionally replaced by N; (Q) are further substituted with R1 at one or more unsubstituted positions; and in (II), the group L is bonded to any position of the part of the molecule in square brackets. INDEPENDENT CLAIMS are included for:    (1) oligomers, polymers or dendrimers comprising one or more (Q); and    (2) formulation comprising (Q) or their oligomers, polymers or dendrimers and at least one solvent.