Synthesis And Photovoltaic Performance Of Novel Polymer Metal Complex Dyes Of Thiophene Derivatives

Dye-sensitized solar cells(DSSCs)were proposed in 1991,and have attracted the attention of a large number of researchers due to their simple structure,easy to manufacture,light weight,and continuous breakthroughs in photoelectric conversion efficiency.Among them,dye sensitizer as the core part of photoelectric conversion efficiency is the focus and hotspot of research.At present,the thermal stability of pure organic dye sensitizer is not very good,so its development has certain limitations.Because rare metals are expensive,the production of ruthenium-based complex has serious harm to the natural environment,so it is difficult to achieve large-scale industrial applications.In order to solve the above problems,this paper designed,synthesized and characterized three types of dye sensitizers,and obtained the required polymeric metal complexes through homopolymerization and copolymerization reactions.The research contents are as follows:1.After coordination of thiophene and imidazole derivatives and five cheap metals as auxiliary electron acceptors and BDTT as electron donor,a series of polymeric metal complex dye sensitizers of D-A’-π-A structure were obtained by Yamamoto polymerization reaction.The synthesized intermediate products are characterized and five polymer metal complexes.The test results show that(a)the polymer metal complexes BDTT-BDTD-Hg has larger light absorption range,smaller energy gap and better light absorption capacity and the best photoelectric conversion efficiency;(b)the buxy group on the auxiliary ligand has better solubility;(c)the thermal stability of the five polymer metal complexes basically meets the application requirements of DSSC.2.In order to further explore the influence of alkyl chain number,homopolymer and copolymerization on dye-sensitized solar cells,thiophene derivatives and five different metals were coordinated as auxiliary electron acceptors,BDTT as electron donor,and two types of polymeric metal complexes of D-A’-π-A structure by Yamamoto polymerization and Heck polymerization were characterized,and based on the photovoltaic performance of DSSC devices were tested.Data analysis is available:(a)the highest photoelectric conversion efficiency of BDTT(12.89%);(b)the homopolymeric metal complexes have lower energy level and better light absorption capacity relative to copolymeric metal complexes;(c)the two sensitizers show excellent thermal stability(T_d>240 C)and meet the working requirements of DSSC.By exploring the effects of coordination metal,alkyl chain number,homopolymerization and copolymerization on the DSSC properties,we prove that the test performance of various homopolymeric metal complexes relative to copolymeric metal complexes is better,due to D-A’-π-A chain uniform arrangement,makes the photoelectric conversion efficiency is higher,the larger the atomic radius,the stronger the coordination bond of metal ions corresponding polymeric metal complex photoelectric conversion efficiency is higher,shows that this kind of metal complex is more suitable for auxiliary receptor A’,for the research and development of metal complex sensitizer.