| abstract |
Copolymers of formula (I): n nwhere each A is S, Se or C═C; each x is an integer from 1 to 4; each R1 is independently H, F, CN or a C 1 -C 20 linear or branched aliphatic group; Ar is one or more substituted or unsubstituted aromatic units; and, n is an integer 5 or greater, can be formed into films or membranes that are useful as active layers in organic electronic device, such as PV solar cells, providing high power conversion efficiencies and good thermal stability. Such copolymers may be synthesized from monomers of formula (II):n n nby Stille or Suzuki coupling reactions. Such monomers may be synthesized by a variation of the Pinner synthesis. |