Synthesis of main-chain metallo-copolymers containing donor and acceptor bis-terpyridyl ligands for photovoltaic applications

摘要

Two random (Zn ~(II)-based P1-P2) and two alternating (Ru ~(II)-based P3-P4) metallo-copolymers containing bis-terpyridyl ligands with various central donor (i.e., fluorene or carbazole) and acceptor (i.e., benzothiadiazole) moieties were synthesized. The effects of electron donor-acceptor interactions with metal (Zn ~(II) and Ru ~(II)) ions on their thermal, optical, and electrochemical properties were investigated. Because of the strong ICT transitions between donor and acceptor ligands in both Zn ~(II)- and Ru ~(II)-based metallo-coplymers and MLCT transitions in Ru ~(II)-based metallo-coplymers, the absorption spectra covered a broad range of 260-750 nm with the band gaps of 1.57-1.77 eV. In addition, the introduction of Ru ~(II)-based metallo-coplymer P4 mixed with PC _(60)BM as an active layer of the BHJ solar cell device exhibited the highest PCE value up to 0.90%.