Novel Main Chain Polymeric Metal Complexes Based on Zn(II) or Cd(II) with Fluorene and 8-Hydroxyquinoline Ligand: Synthesis, Characterization and Photovoltaic Application in DSSCs

Four novel donor–π-bridge–acceptor(D–π–A) main chain polymeric metal complexes (P1, P2, P3 and P4) as dye sensitizers for dye-sensitized solar cells (DSSCs) based on Zn(II) or Cd(II) complexes with fluorene and 8-hydroxyquinoline ligand have been synthesized by the Heck coupling and characterized by FT-IR, Elemental analysis and GPC. The optical properties, thermal properties, electrochemical properties and photovoltaic properties of these polymeric metal complexes have been investigated and studied by TGA, DSC, C–V curves and I–V curves. DSSCs based on P1 and P3 show good photovoltaic performances and the corresponding power conversion efficiency (PCE) are up to 1.99 % (Jsc = 4.59 mA cm−2, Voc = 0.68 V, FF = 0.636) and 2.05 % (Jsc = 5.25 mA cm−2, Voc = 0.60 eV, FF = 0.65) under simulated AM 1.5 G solar irradiation (100 mW cm−2). Besides, they showed good stabilities with thermal decomposition Temperatures are 421, 441, 413, 385 °C, respectively, which are suitable for DSSCs.