Polymers

A polymer comprising repeating unit(s) of the following formula

• R1, R2, R3, R4, R5 and R6 are independently of each other hydrogen, F, SiR100R101R102, or an organic substituent, or
• R1 and R2, R3 and R4, and/or any of the substituents R1, R2, R3, R4, R5 and/or R6, which are adjacent to each other, together form an aromatic, or heteroaromatic ring, or ring system, which can optionally be substituted,
• m is 0, or an integer of 1, or 2,
• n1 and n2 are 0, or an integer 1, or 2,
• R100R101R102are independently of each other C1-C18alkyl, substituted or unsubstituted C6-C18aryl, and
• Ar1 and A2 are each independently of each other a substituted or unsubstituted arylene, or heteroarylene group,
• with the proviso that at least one of R1, R2, R3 and R4 is different from H, and
• wherein the polymers have a weight average molecular weight of 2,000 Daltons or greater.