| Flexible solar cells with high quality,flexible,wide applicability and so on have been widely used in the fields of wearable electronic fabrics,flexible display,mobile power supply equipment,deformable sensors and so on.The perovskite solar cell is an ideal material for the preparation of flexible solar cells because it not only has high energy conversion efficiency,but also has a lower processing temperature（<150 ° C）and can be applied to the preparation process of flexible substrates.In this paper,a large number of experimental research on the preparation of high efficiency flexible perovskite solar cells has been carried out.Based on this study,the development of large-scale devices and the improvement of life have been done.This thesis mainly includes the following four aspects:（1）Aiming at the key scientific problems that the perovskite film prepared by the two-step method is incompletely reacted and the process repeatability is poor,the disordered amorphous PbI2 thin film was prepared by replacing the low-boiling point DMF solvent with high-boiling point and low-volatility DMSO solvent,A two-step film-forming technique was developed to facilitate rapid diffusion of CH3NH3 I to achieve complete reaction of the perovskite film,and a high quality perovskite film was prepared.The effect of PbI2 solvent in the perovskite film prepared by two-step method on the crystallization quality of perovskite film was studied experimentally,and the mechanism was analyzed.The use of high boiling low volatile DMSO solvent instead of the traditional solvent DMF,DMSO solvent and PbI2 to form DMSO-PbI2 intermediates,inhibited the PbI2 rapid self-aggregation to form PbI2 crystals and the formation of disordered amorphous PbI2 film,significantly accelerated the CH3NH3 I to PbI2 layer The internal diffusion rate increases the complete rate of perovskite reaction.The results show that the quality of the perovskite absorption layer is obviously improved,and the efficiency of the assembled PSC is greatly improved to 15.1%.（2）Aiming at the key scientific problems of poor controllability and small grain size of perovskite films prepared by traditional one-step method,the introduction of high-boiling dihalogen additives chelating with lead halides has been investigated and a one-step film-forming technique has been developed to promote more uniform nucleation of the perovskite crystals with larger grain sizes.The effects of one-step perovskite precursor formulation on the properties of perovskite films and their assembled batteries were investigated in depth.Based on the reaction kinetics of perovskite with PbI2,Pb Cl2 and MAI,the formula of mixing the two lead halides was proposed.The type of dihalogen additive chelating with lead halides was introduced and optimized,Adding timing and perovskite absorption layer film forming process;combining with the characteristics of easy crystallization of PbI2,a novel perovskite absorbing layer formulation containing excessive PbI2（PbI2/Pb Cl2/MAI = 1.114:1:4）perovskite film,the photoelectric conversion efficiency of the PSC up to 20.3%,up to the leading domestic level.（3）Aiming at the technical bottleneck that the surface roughness of flexible transparent electrodes greatly affect the battery leakage current,a perovskite precursor solution consisting of three kinds of low,middle and high boiling point solvents was designed and developed.The high transparent electrode based on flexible quality perovskite thin film preparation technology.The PET/ITO flexible transparent electrode with low resistance,low roughness and high heat resistance was optimized.PEDOT:PSS/Ni O with double-layer structure was independently designed.PEDOT:PSS wet process was used to melt PET/ITO as a whole,the superposition of Ni O dry process will be partially exposed to PEDOT:PSS ITO partial passivation,significantly reducing the PET/ITO assembly of flexible PSC leakage current;the first time in the world of perovskite light The dual-additive was introduced into the precursor solution and the crystallization rate and growth size of the perovskite crystal were controlled by the gradient evaporation of the solvent.The crystalline quality of the perovskite was significantly improved.The conversion efficiency of flexible PSC for PET substrate reached the highest in the world by 18.9%.（4）Aiming at the problem of low conversion efficiency and poor stability of large-area perovskite devices,the series structure of transparent electrodes on large-area devices was designed and studied.Large area perovskite absorption layer was prepared by slit coating method.Atmospheric pressure liquid packaging technology,produced a large area of flexible and efficient devices in series.Based on the 5cm×5cm ITO transparent anode,three series-connected PSC cells with 1.2 cm width and 12 cm2 effective area were fabricated by designing the series device pattern,device structure,cell shape and broad band.The glass substrate PSC device Photoelectric conversion efficiency up to 11.2%,flexible substrate PSC device efficiency of 8.29%.From the internal modification and external packaging,we studied the technology of improving the stability of 5cm×5cm area flexible PSC series devices.The perovskite absorber layer is premodified by designing a composite hole transport layer（Mo O3/PEDOT:PSS）,and the perovskite absorber layer is post-modified by designing a double layer electron transport layer（PCBM/TIPD）and high barrier packaging film,optimize the packaging process,packaging flexible PSC device life of 500 h. |
