Synthesis And Study On The Photoelectric Performance Of Novel Dyes Of Polymeric Metal Complexes Containing Cyclopentadithiophene

Solar energy is recognized as one of the promising energy in the twenty-first century,due to its universality, non-polluting and security, at the same time, solar cell is a device that can turn sunlight into electricity. Dye-sensitized solar cells(DSSCs) has been extensively studied because of its low production cost, flexible structure. Sensitizer is one of the most critical components of the dye-sensitized solar cells, which play an important role by capturing sunlight and transferring electrons. To improve the photovoltaic performance of dye-sensitized solar cells that using polymeric metal complexes as sensitizers, we have designed and synthesized two series of polymeric metal complexes to improve the photoelectric conversion efficiency of it, the main contents are as follows:(1) The four D-π-A polymeric metal complexes(P1-P4) are synthesized by Yamamoto reaction, using cyclopentacarbyl thiophene or fluorene derivatives as donor(D), the metal complexes with 1,10-phenanthroline derivative and DAMN as receptors(A), thiophene group as π bridge. Then we test their thermal stability and optical performance by UV-visible absorption, cyclic voltammetry, thermal gravimetric analysis and photovoltaic performance analysis. The results show that they all have good thermal stability. In the AM 1.5G simulated sunlight, the DSSCs using cyclopentacarbyl thiophene derivative as sensitizer exhibit higher photoelectric conversion efficiency(P12.41%, P2 2.31%) than the DSSCs using fluorene derivative as sensitizer(P3 1.65%, P41.52%), which can be attributed to the stronger ability of providing electrons of cyclopentacarbyl thiophene derivative.(2) The four D-A polymeric metal complexes(P1-P4) using cyclopentacarbyl thiophene or fluorene derivative as donor and 2-(2’-pyridyl) benzimidazole derivative as acceptor are also synthesized by Yamamoto reaction. By their thermal and photovoltaic performance analysis results, it shows that they also have better thermal performance. In the AM 1.5G simulated sunlight, the photoelectric conversion efficiency of P1-P4 are2.49%, 2.34%, 2.05% 1.80%, respectively, we can find that the polymers(P1, P2) using cyclopentacarbyl thiophene derivative as donor exhibit better optical performance, and the polymers(P1, P3) with Cd(II) exhibit good optical and electrical properties than the corresponding polymer(P2, P4) with Zn(II).The results show that the eight polymeric metal complexes all have good thermal stability, however, compared with the conventional dyes, the photoelectric conversionefficiency of them is not too high, but it pave a new path to design novel conjugated organic polymer for high efficient and stable dye-sensitized solar cells.