Conjugated polymers and their use in optoelectronic devices

An organic photovoltaic device comprising an anode, a cathode, and in between the anode and the cathode a semiconductor component, the semiconductor component comprising an oligomeric or polymeric compound comprising in its backbone a first repeat unit of the formula:

• wherein:
• each Ar independently is a monocyclic aryl or heteroaryl group;
• Ra is selected from H, a C1-40 alkyl group, a C2-40 alkenyl group, a C2-40 alkynyl group, and a C1-40 haloalkyl group, wherein:
• each of the C1-40 alkyl group, the C2-40 alkenyl group, the C2-40 alkynyl group, the C1-40 haloalkyl group, optionally can be substituted with 1-10 substituents independently selected from a halogen, —CN, NO2, OH, —NH2, —NH(C1-20 alkyl), —N(C1-20 alkyl)2, —S(O)2OH, —CHO, —C(O)—C1-20 alkyl, —C(O)OH, —C(O)—OC1-20 alkyl, —C(O)NH2, —C(O)NH—C1-20 alkyl, —C(O)N(C1-20 alkyl)2, —OC1-20alkyl, —SiH3, —SiH(C1-20 alkyl)2, —SiH2(C1-20 alkyl), and —Si(C1-20 alkyl)3;
• and
• one or more non-adjacent —CH2— groups in the C1-40 alkyl group, the C2-40 alkenyl group, the C2-40 alkynyl group, and the C1-40 haloalkyl group can be replaced by a group independently selected from —O—, —S—, —NH—, —N(C1-20 alkyl)-, —C(O)—, —C(O)O—, and —Si(C1-20 alkyl)2—;
• and
• each of Rb and Rc independently is selected from H and -L-R,
• wherein:
• L at each occurrence, independently is selected from O, S, and a covalent bond;
• and
• R, at each occurrence, independently is a C1-40 alkyl group;
• wherein the oligomeric or polymeric compound comprises in its backbone a second repeat unit, the second repeat unit comprising (a) one or more optionally substituted polycyclic aryl or heteroaryl groups, (b) one or more optionally substituted monocyclic aryl or heteroaryl groups, and/or (c) one or more linear conjugated linkers.