Azaperylenes as organic semiconductors

A compound of the formula I′

• wherein
• each of R1, R2, R3 and R4 independently is selected from H, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted alkynyl, unsubstituted or substituted aryl, halogen, Si(R11)3, XR6;
• or one or more of R1 and R2, R2 and R3, R3 and R4, together with the carbon atoms they are bonding to, form a saturated or unsaturated, unsubstituted or substituted carbocyclic or heterocyclic ring;
• R5 is H, OR7, SR7, NR7R8, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted alkynyl, or unsubstituted or substituted aryl;
• R6 is Si(R11)3, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted alkynyl, unsubstituted or substituted aryl;
• R7 is H, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted alkynyl, unsubstituted or substituted aryl;
• X is O, S, NR8;
• R8 is H, unsubstituted or substituted alkyl, unsubstituted or substituted alkenyl, unsubstituted or substituted alkynyl, unsubstituted or substituted aryl,
• R11 being C1-C20-alkyl or -alkoxy,
• provided that at least one of R1, R2, R3, R4, R6, R7 is C4-C22alkyl, C10-C22-phenylalkyl, or such residues interrupted by O, S, NR10, COO, OCNR10, OCOO, OCONR10, or NR10CNR10.