Organic semiconductors

A conjugated copolymer comprising one or more units of formula I and one or more units of formula II that are distributed in random sequence along the polymer backbone

• wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings
• Ar1 is a group selected from the following formulae and their mirror images
• Ar2 is a group selected from the following formulae and their mirror images
• X1, X2 are H, F, Cl or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated,
• W is S, O, Se, CR1R2 or NR1,
• R1-10 is H, F, Cl, straight-chain, branched or cyclic alkyl with 1 to 30 C atoms, in which one or more CH2 groups are optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR0—, —SiR0R00—, —CF2—, —CR0═CR00—, —CY1═CY2— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, and in which one or more CH2 or CH3 groups are optionally replaced by a cationic or anionic group, or aryl, heteroaryl, arylalkyl or heteroarylalkyl, wherein each of the aforementioned cyclic groups has 5 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is unsubstituted or substituted by one or more identical or different groups L,
• L is F, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, R0, OR0, SR0, —C(═O)X0, —C(═O)R0, —C(═O)—OR0, —O—C(═O)—R0, —NH2, —NHR0, —NR0R00, —C(═O)NHR0, —C(═O)NR0R00, —SO3R0, —SO2R0, —OH, —NO2, —CF3, —SF5, or optionally substituted silyl, or carbyl or hydrocarbyl with with 1 to 30 C atoms that is optionally substituted and optionally comprises one or more hetero atoms,
• Y1, Y2 are H, F, Cl or CN,
• X0 halogen,
• Z1 S,
• R0, R00 are H or straight-chain or branched alkyl with 1 to 20 C atoms that is optionally fluorinated,
• a, b are 1 or 2.