Study On Counter Electrode Of Dye And Perovskite Sensitized Solar Cells Based On Carbon Materials

In recent years,with the increasing depletion of fossil energy and the gradual serious environmental problems,the development and utilization of clean,renewable energy becomes an effective means to alleviate these two problems.Solar as the largest reserves of clean and renewable energy,its total amount of annaul irradiance to the earth's surface is far more than the earth's reserves of fossil fuels.Solar cells can convert solar energy effectively into electrical energy.Therefore,its research has been a hot spot in the field of scientific research,its development is very fast.Divided by sensitized materials,sensitized solar cells contain dye,quantum dots and perovskite sensitized solar cells.Typical sensitized solar cells are composed of five parts,including Transparent Conductive Optical Glass,Photoanode,Sensitizer,Electrolyte or Hole Transport Material?HTM?and the Counter Electrode?CE?.CE is responsible for collecting electrons from the external circuit and promoting the regeneration of redox couple or recombining with the holes from HTM.Carbon material has characteristics of low price,wide range of raw materials,simple preparation process,good conductivity and corrosion resistance,so it is often used as CE material for new solar cells.Based on it,this topic mainly carried out the following two works on CEs of dye and perovskite sensitized solar cells.Firstly,for the shortcoming of high cost of Pt CE of Dye-sensitized solar cells?DSSCs?,the high-conductivity multi-walled carbon nanotubes?MWCNTs?and low-cost titanium dioxide?TiO₂?nanoparticles were used as supporting and attaching materials respectively,and the MWCNTs/TiO₂ composites were synthesized by the method of solvent treatment.The CE of MWCNTs/TiO₂ composites was prepared by a simple doctor blading technology.The composite CE had a high specific surface area,large pores and good catalytic activity.The resulting DSSCs device based on MWCNTs/TiO₂ composite CE obtained 7.95%power conversion efficiency?PCE?,which was higher than that of MWCNTs CE based device?PCE is 6.82%?by 16.6%.Secondly,to avoid the disadvantage of the leak of liquid electrolyte,a kind of all-solid perovskite solar cells?PSCs?came into reality.The preparation process was simple and the period shortened compared with DSSCs.However,the use of precious metals as CE hindered its commercialization process seriously.Here,we explored the PSCs with CE of commercial carbon paste,and the complete PSCs device fabricated by simple spin coating and the doctor blading technology.Finally,the PSCs device obtained 5.09%of the PCE with a short current density of 17.6 mA/cm² and an open circuit voltage of 0.83 V and a fill factor of 0.35.