Study On Cholesterol Co-sensitized Solar Cells And Synthesis Of Dyes With Y-shaped Alkyl Chains

Solar cells,as clean,pollution-free,and emerging energy conversion devices,have received widespread attention.Sensitizers are employed as an important component of dye-sensitized solar cells?DSSCs?,which have a significant impact on their photoelectric conversion efficiency.At present,dye sensitizers can be divided into two categories,i.e.,metal complex sensitizers?including ruthenium-pyridine and zinc-porphyrins complex?and metal-free organic dye sensitizers.Among them,metal-free organic dye-sensitized solar cells have attracted a lot of attention because of their many advantages,such as high molar extinction coefficient,abundant raw materials,easy preparation,and easy modification of molecular structure.This paper studies the interface electron transmission of dye-sensitized solar cells and improves the photoelectric conversion efficiency of DSSCs.The specific contents and results are as follows:?1?Co-sensitized with cholesterol and dye NP-1 to prepare solar cells.The addition of cholesterol can greatly reduce molecular aggregation between dyes,which is conductive to increasing the open circuit voltage(V_oc)of DSSCs.The cholesterol has no absorption in the UV-Vis range,and can cover the surface of TiO₂that does not adsorb NP-1,which can effectively inhibiting the recombination of photoelectrons and electrolytes and increasing the number of electrons injected into the TiO₂film,improving the short circuit current density(J_sc)and fill factor?FF?of the devices.Eventually,the photoelectric conversion efficiency of solar cells is improved from 3.20%to 4.40%.?2?A series of Y-shaped alkyl chains dyes with different?-linkers and molecular size are designed and synthesized by alkylation reaction,Ullman reaction,low-temperature lithium substitution reaction,Suzuki reaction,and Knoevenagel condensation reaction.The molecular structures of intermediate and final products were confirmed by IR and MS.These dye sensitizers with Y-shaped alkyl chains are expected to inhibit the recombination of optoelectronics.Overall,this thesis employed cheap and readily-available cholesterol as the co-sensitizer,which can be conductive to inhibiting optoelectronics recombination and molecular aggregation,thus obtaining improved and long-life DSSCs.In addition,the design and synthesis of dyes with Y-shaped alkyl chains have the promoting significance for the development of organic dye sensitizers.