Three novel conjugated copolymers containing coplanar bithiophenevinyl-(2-pyran-4-ylidenemalononitrile) unit linked with different electron-donating moieties by a double bond were synthesized by Heck polycondensation reactions. By introducing a double bond between the donor and acceptor unit within the backbone of polymers instead of a single bond, the conjugated length was enhanced, and consequently broader absorption spectral range and reduced band gap. Hence, the polymer can absorb more light to get higher Jsc and power-conversion efficiency.
- Weidong Cheng
- Shiyu Yao
- Wenjing Tian
