TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The first comonomer repeat unit comprises a thiazole moiety of formula (XXIII). The second comonomer repeat unit comprises silacyclopentadithiophene moiety, a benzothiadiazole moiety, thiadiazoloquinoxaline moiety, cyclopentadithiophene moiety, cyclopentadithiophene oxide moiety, benzoisothiazole moiety, benzothiazole moiety, thiophene oxide moiety, thienothiophene moiety, thienothiophene oxide moiety, dithienothiophene moiety, dithienothiophene oxide moiety, tetrahydroisoindole moiety, fluorenone moiety, thiazole moiety, selenophene moiety, silole moiety, thiazolothiazole moiety, cyclopentadithiazole moiety, naphthothiadiazole moiety, thienopyrazine moiety, oxazole moiety, imidazole moiety, pyrimidine moiety, benzoxazole moiety, or benzimidazole moiety. The second comonomer repeat unit comprises a moiety selected from 34 moieties as given in the specification e.g. cyclopentadithiazole moiety of formula (I), benzothiadiazole moiety of formula (II), thiadiazoloquinoxaline moiety of formula (III), cyclopentadithiophene dioxide moiety of formula (IV), cyclopentadithiophene monoxide moiety of formula (V), benzoisothiazole moiety of formula (VI), benzothiazole moiety of formula (VII), thiophene dioxide moiety of formula (VIII), cyclopentadithiophene dioxide moiety of formula (IX), cyclopentadithiophene tetraoxide moiety of formula (X), tetrahydroisoindole moiety of formula (XVI), silacyclopentadithiophene moiety of formula (XVIII) and cyclopentadithiophene moiety of formula (XXI) (preferably cyclopentadithiazole moiety (I), cyclopentadithiophene moiety (XXI) or silacyclopentadithiophene moiety (XVIII)). The third comomoner repeat unit comprises a thiophene moiety.R5=H, 1-20C alkyl, 1-20C alkoxy, 3-20C cycloalkyl, 1-20C heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO2R (preferably hexyl);R=H, 1-20C alkyl, 1-20C alkoxy, aryl, heteroaryl, 3-20C cycloalkyl or 1-20C heterocycloalkyl;X and Y1=CH2, O, or S;R1, R2, R'5 and R6=R5;R7 and R8=H, 1-20C alkyl, 1-20C alkoxy, aryl, heteroaryl, 3-20C cycloalkyl or 3-20C heterocycloalkyl.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The polymer (A1) further comprises a third comomoner repeat unit different from the first and second comonomer repeat units. EXAMPLE - No suitable example given.