Polymer solar cells based on copolymers of dithieno[3,2-b:2 ',3 '-d]silole and thienopyrroledione

Novel low band gap copolymers based on dithienosilole and thienopyrroledione units were synthesized. Copolymer P1 with branched side chains on the TPD units demonstrated a PCE of 4.4% with a high V-oc of 0.89 V for OPV applications while OTFT devices fabricated from a copolymer containing linear side chains (P2) performed better in OTFT device configurations.