Synthesis and Photovoltaic properties of branched chain polymeric metal complexes containing Phenothiazine and Thiophene derivative for dye-sensitized solar cells

Abstract

Three donor-π-acceptor (D-π-A) dyes (P1-P3) of polymeric metal complexes were synthesized for application in dye-sensitized solar cells (DSSCs). These D-π-A sensitizers use Phenothiazine appended with octyl as donor (D), C=C bond as π-bridge(π), and thiophene-phenanthroline metal complexes as acceptor (A) that can be anchored to the TiO 2 surface. They have been characterized and studied by FT-IR, GPC, Elemental analysis, TGA, UV-vis absorption spectroscopy, photoluminescence spectroscopy and cyclic voltammetry. When applied in the DSSCs, the sensitizer P1 exhibits the best energy conversion efficiency of 1.57% (Jsc = 4.12 mA/cm 2, Voc = 0.62 V, FF = 61.7%) under simulate AM 1.5G solar irradiation. The TGA data show that these new dyes own good thermal stability. These results will facilitate the understanding of the crucial importance of molecular engineering and pave a new path to design novel conjugated organic polymer dye for highly efficient and stable DSSCs. [Figure not available: see fulltext.]