Synthesis and photovoltaic properties of thieno[3,2-b]thiophenyl substituted benzo[1,2-b:4,5-b′]dithiophene copolymers

A new thienothiophene–benzodithiophene electron donor building block was synthesized and incorporated into 2-dimensional conjugated donor–acceptor polymers. The polymers were fully characterised and tested in bulk heterojunction solar cell devices.