Preparation Of High-Efficiency Perovskite Solar Cells Based On Ink Engineering By Enkjet Printing Technology

In the past 11 years,the conversion efficiency of perovskite solar cells has rapidly increased from the initial 3.8%to 25.2%,which has attracted extensive attention from academia.However,the perovskite thin film is often prepared by spin coating.The thin film prepared by this spin-coating method faces a series of problems such as low material utilization rate and difficulty in large-scale expansion.The inkjet printing technology is adopted by us to manufacture high-efficiency large-area perovskite devices due to its precise ink droplet control system and the advantages of large-scale production.In inkjet printing perovskite devices,due to the long waiting time for printing,the process of crystal growth of the perovskite liquid film printed on the substrate will be challenging to control,which will significantly damage the quality of the perovskite film To find an effective way to optimize the crystallization behavior of precursor solutes during inkjet printing,we have studied here a method to reduce the nucleation rate of precursor solutions by optimizing the solvent and solute of perovskite inks and The rate of crystal precipitation to prepare a high-performance inkjet-printed perovskite solar device.In this paper,the TiO₂/C₆₀ composite film of the electron transport layer of the perovskite solar device was prepared by the evaporation method and the chemical bath method.Besides,the effects of solvent adjustment of perovskite ink and solute pretreatment on the crystal structure,extinction performance,transmission resistance,and photoelectric performance of the annealed device were also studied.Details as follows:1.By introducing Cs_0.05(MA_0.17FA_0.83)_0.95PbI_2.55Br_0.45 type perovskite structure in the field of inkjet printing perovskite,the structure is FTO/TiO₂/C₆₀/Cs_0.05(MA_0.17FA_0.83)_0.95PbI_2.55Br_0.45/Spiro-OMe TAD/Au device to replace the traditional MAPbI₃,thanks to this excellent light absorption layer,improve the device extinction intensity and energy level matching degree,and strengthen the hole transport layer The hole transport rate of the whole showed excellent photoelectric performance.The photoelectric conversion efficiency of 13.9%was obtained.2.By introducing high boiling point and high viscosity NMP solvent and DMF solvent in the ink system to form a mixed solvent at a ratio of 1:1,the crystallization time of the solution is extended,thus avoiding the long-term inkjet printing process because of Natural crystallization leads to increased defect sites of the resulting perovskite thin film and defects such as increased surface roughness.In the end,we achieved a photoelectric conversion efficiency of inkjet-printed perovskite cells of 16.2%and a device attenuation of less than 30%at 1000 h under low humidity.3.By introducing DMSO to pre-treat the solute in the ink system,the rapid reaction of solute molecules such as PbI₂,PbBr₂ and organic cations in ink is substantially avoided,thereby reducing the nucleation rate of perovskite crystal nuclei,which the perovskite film prepared after pretreatment showed a larger grain size and a smoother film surface.The device composed of this perovskite film showed a higher composite impedance and a longer Carrier transmission life,the final perovskite solar cell achieved a photoelectric conversion efficiency of 19.6%.At the same time,we also prepared devices with active areas of 1.01,2.02,and 4.04 cm² and obtained energy conversion efficiencies of 17.9%,15.4%,and 14.3%,respectively.