Synthesis And Study On The Photovoltaic Properties Of Novel Dyes Of Polymeric Metal Complexes Containing Benzodithiophene

In recent years, Dye-sensitized solar cells(DSSCs) have become one of the most promising potential of renewable energy in Photovoltaic field since it have the advantages of low cost, high efficiency and environmentally friendly compared with traditional of inorganic solar cells. As a key component in these cells, the sensitizers play an important role of capturing solar energy and generating electric charges. Up to now, the noble-metal ruthenium polypyridyl dyes have proved to be the best dyes in DSSCs. However, the widespread application of Ru is limited owing to its scarcity,high cost, and difficulty in purification. In contrast, polymeric metal complexes photo-sensitizers with the transition metal are promising for application and becoming more and more popular in DSSCs for their advantages, such as diversity of molecule structures, simple synthesis, good thermal stability as well as low cost. Therefore,designing and synthesizing polymeric metal complexes dyes with high efficiency to replace Ru-based dyes have important theoretic and practical meaning. In this thesis designed and synthesized two kinds of new type of light absorption performance and good heat stability of polymer metal complex dyes, the works are listed as following:1. Four novel of D-π-A type polymeric metal complexes dyes have been designed and synthesized by Yamamoto aggregation reaction, which used benzodithiophene and hydroquinone derivatives as electron donors, thiophene vinyl as π bridge, Zinc and cadmium based 8-hydroxyquinoline metal complexes as electron acceptor, and their photovoltaic performances were characterized and analyzed, the results show that the obtained polymer dyes have good thermal stability that can satisfy the basic requirement of solar photovoltaic devices. The DSSCs based on the polymeric metal complexes by P1, P2, P3 and P4 exhibit the power conversion efficiency of up to2.34%, 2.46%, 1.51% and 1.65% respectively. The polymers(P1, P2) exhibit higher photoelectric conversion efficiency than the polymers(P3, P4), which can be attributed to the fact that benzodithiophene derivatives have stronger ability of providing electrons than the hydroquinone derivatives.2. Four novel of D-D-π-A type polymeric metal complexes dyes have been designed and synthesized, which used fluorene, 4,8-dioctylbenzodithiophene and1,4-dioctylbenzene as electron donors, C=C as π-bridge, and 8-hydroxyquinoline metal complexes as electron acceptor, and their photovoltaic performances werecharacterized and analyzed, the results show that the obtained polymer dyes have good thermal stability that can satisfy the basic requirement of solar photovoltaic devices. The DSSCs based on the polymeric metal complexes by P1, P2, P3 and P4 exhibit the power conversion efficiency of up to 2.38%, 2.62%, 1.53% and 1.72%respectively, Further more, the polymers with cadmium exhibit better optical and electrical properties than the corresponding polymers with zinc.The results showed that the two series of polymeric metal complexes dyes have a certain photovoltaic performance and high thermal stability, Although the energy conversion efficiency needs to be improved compared to the traditional ruthenium pyridine complexes, these new kind of photosensitive dye has good prospects for development.