Synthesis And Study On The Photovoltaic Properties Of Main Chain Polymeric Metal Complexes Dye-sensitizer Containing Fluorenevinylene Or Phenylenevinylene

With the rapid development of society, the need of energy is growing. However, fossilfuels as the mainstream of energy sources have become increasingly depleted, and theenvironmental problems caused by the use of fossil fuels have taken impact seriously on dailylives of people. Therefore, development of new renewable energy is urgent. Among manyrenewable energies such as sunlight, wind, rain, tides, and geothermal heat, the sun energy isthe most potential energy, because the sun energy is a clean and inexhaustible new energysource and without geographical restrictions.Solar cells as the main mode in the utilization of solar energy are devices based on solartechnology which convert sunlight directly into electricity under the photo-voltaic effect.Dye-sensitized solar cells (DSSCs) have been studied widely for the recent years due to lowcost, the wide source of raw materials, a large flexibility in shape, color, and the low pollutionof environment. Photosensitive dyes as the soul part of DSSCs are an important aspect of thestudy. Ru complexes are the most common photosensitive dye due to the high powerconversion efficiency. However, the development of Ru complexes as dyes has encounteredmany bottlenecks due to the rarity and high cost of the ruthenium metal and the difficultsynthesis and purification for Ru Complexes. Polymeric metal complexes solve thesedifficulties. Polymeric metal complexes as the photosensitive dye have donor-π-bridge-acceptor (D-π-A) structure which the common character of these organic dyes. Electronicconductivity of polymeric metal complexes can be improved by charger transfer actionbetween Donor and Acceptor (ICT). Polymeric metal complexes can adjust HOMO andLUMO level and broaden the absorption spectra by copolymerization with differentmonomers. Meanwhile, polymeric metal complexes can also improve the photovoltaicperformance by charger transfer action between metal and ligand (MLCT). On the basis ofabove mentions, we design and synthesize two types of the novel main chain polymeric metalcomplexes which were characterized by FI-IR,1H-NMR,EA,GPC. Optical properties, thermalproperties, electrochemical properties and photovoltaic properties as dyes applied in DSSCsof these polymeric metal complexes have been investigated and studied by TGA, DSC, CVcurves and I-V curves. The main work was summarized as follows:1. We have designed and synthesized four novels D-π-A polymeric metal complexesP1-P4which contain fluorene or phenylene-fluorene as Donor, Zn(II)–8-HQ complex orCd(II)–8-HQ complex as Acceptor. Power conversion efficiencies based on polymeric metalcomplexes P1-P4as photosensitive dyes are1.99%,1.92%,2.05%and1.90%, respectively.Polymeric metal complexes P1-P4show good thermal stability by TGA and DSC, which is fitfor the stability and fabrication processes of DSSCs and other optoelectronic devices. 2. We have designed and synthesized four novels D-A polymeric metal complexes P1-P4which contain fluorene-carbazole unit or phenylene-carbazole unit as DonorZn(II)–phenanthroline complex or Cd(II)–phenanthroline complex as Acceptor. Powerconversion efficiencies based on polymeric metal complexes P1-P4as photosensitive dyes are0.82%,1.05%,0.99%,1.15%, respectively. On the basis of these results, we can see thatpolymeric metal complexes as a kind of the novel organic material applied in DSSCs arepotential to development.