Novel dyes of branched chain polymeric metal complexes based on cyclopentadithiophene derivatives: synthesis, characterization and photovoltaic performance for dye-sensitized solar cells

摘要

In this work, four novel D-A polymeric metal complexes (P1-P4) were designed and synthesized as dye sensitizers for high-performance dye-sensitized solar cells (DSSCs), which use cyclopentadithiophene or fluorene derivatives as donor (D) and the 2-(2'-pyridyl)benzimidazole derivative as acceptor (A). All polymers exhibited good thermal stability for their application in DSSCs. DSSCs based on P1 exhibited the best power conversion efficiency of 2.49 % with the cyclopentadithiophene derivative as donor and Cd(II) as coordination ion, which can be attributed to their stronger absorption in the UV-visible region and lower band gap. This study will pave a new path to design novel conjugated organic polymers as dyes for DSSCs.