Influence Of Molecular Sieve Doping Electrolyte On Photoelectric Properties And Stability Of Dye-sensitized Solar Cells

As a new type of thin-film solar cell,dye-sensitized solar cells have many advantages such as high theoretical conversion efficiency,light weight,simple preparation process and environmentally friendly.However,the stability and performance is easily affected by severe temperature and humidity when operating under actual conditions.In order to prepare dye-sensitized solar cells with high stability and high optoelectronic performance,people have further improved the short-circuit current density and photoelectric conversion efficiency of dye-sensitized solar cells by developing novel dye molecules,improving electrolytes,and optimizing counter electrodes.Scattering layers can usually be used on the photoanode to capture scattered light to improve short-circuit current density,but cannot effectively improve device stability.In this paper,using the excellent adsorption and separation ability of molecular sieves with adjustable denaturation,two kinds of molecular sieve materials with different structures are separately doped into the electrolyte.Utilization and photoelectric conversion efficiency,and the adhesion of stable dye molecules is achieved to improve the long-term stability of the device.The main research contents are as follows: The ability of adsorbing water molecules of three molecular sieves and the different morphological phenomena obtained by grinding at different times were compared by thermo-gravimetric analysis and scanning electron microscope characterization,and then Beta and SBA-15 molecular sieves were selected as dopants respectively.By doping molecular sieves with different mass ratios,a dummy battery without a photoanode was prepared,and its transmission spectrum was measured to explore the light refraction properties of doping with different grinding times and different mass ratios.At the same time,dye-sensitized solar cell devices were prepared after doping molecular sieves with different mass ratios,and their optoelectronic properties were characterized by cyclic voltammetry and voltammetry characteristic curves.The results show that the appropriate addition of molecular sieve does not affect the electron pair diffusion and redox reaction rates in the electrolyte.9% Beta molecular sieve has obvious pore structure and surface structure of large crystalline particles,which makes it have a good refraction effect on light,increasing the utilization rate of light by the device,and the photoelectric conversion efficiency reaches 6.78%,which is higher than that of undoped devices（5.49%）.The photoelectric conversion efficiency of dye-sensitized solar cells doped with 6% SBA molecular sieve reached 7.58%,which was higher than that of undoped devices（5.99%）.Finally,by comparing the long-term light absorption properties of the photoanode films in methoxypropionitrile solutions with and without doped molecular sieves,it is found that the dye molecules have better light absorption retention in the solutions containing molecular sieves.The porous structure can absorb the water molecules infiltrated in the device,reduce the phenomenon that the dye is shed by the water molecules,and avoid the reduction of the dye on the photoanode.This study will pave the way for the efficient preparation of long-term stability dye-sensitized solar cells.