| abstract |
The present invention relates to organic solar cell comprising at least one photoactive region comprising an organic donor material in contact with an organic acceptor material and forming a donor-acceptor heterojunction, wherein the photoactive region comprises at least one compound of the formulae Ia and/or Ib where M, (R a ) m and (R b ) n as described in the claims and description. Furthermore, the present invention relates to compounds of formulae Ia and Ib, wherein M, (R a ) m and n are as described in the claims and description and R b is fluorine and to a process for preparing them. |