Solvent Modified Regulation Of Nucleation Crystallization Of Perovskite Films And Fabrication Of Battery Devices

The organic-inorganic hybrid perovskite（perovskite）light absorbing semiconductor developed in the past decade has become the focus and focus of research in the field of new energy due to its excellent characteristics such as high photoelectric conversion efficiency,adjustable absorption band gap,low material cost and manufacturing process cost.Research institutes and enterprises at home and abroad have carried out the development and industrialization of single-junction thin film batteries for such materials.However,the industrialization of perovskite solar cells（PSCs）has some problems,such as poor stability and low yield of large-area preparation,which seriously hinders the process of industrial application of this technology.However,the preparation of small-area high-efficiency perovskite cells requires the use of anti-solvent or blowing assistance.This process is difficult to scale up to the continuous preparation of large-area perovskite films,and there will also be a large number of defects at the interface between the functional layers in the perovskite cells,which will affect the transmission of electrons and holes and greatly affect the performance of devices.In view of this,we take（FAPbI₃）_0.95(MAPb Br_2.2Cl_0.8)_0.05 system as the research object to study the effect of solvent additives on the nucleation and growth kinetics of perovskite crystals;At the same time,appropriate perovskite interface passivation materials are selected to passivate the vacancy defects of perovskite films and reduce the non-radiative recombination of carriers to improve the stability of devices.The main research work is as follows:（1）In the process of solution treatment,the solvent is prepared by regulating the mixing of two alkanes,N-methyl-2-pyrrolidone（NMP）and N-methyl-2-piperidone（N1）,with N,N-dimethylacetamide（DMF）in different proportions.And the influence mechanism of solvent additives on the nucleation mechanism and crystallization kinetics of perovskite was studied using in-situ XRD,SEM,and optical microscopy.At the same time,the device preparation process was optimized,resulting in a photoelectric conversion efficiency of 22%.（2）The perovskite films were further passivated with three phenylethylamine salts as passivators.The surface defect states of the thin film were studied by carrier dynamics and defect state density analysis,and the efficiency and stability of the device were also investigated.The final photoelectric conversion efficiency reached 23.17%,and after 500hours,approximately 83%of the efficiency was retained at an unpackaged relative humidity of 50%and a temperature of 30℃,with improved stability（3）Based on the solvent strategy of the developed perovskite solar cell,a one-step spin coating method without auxiliary nucleation was used to prepare large-area perovskite thin films,and the preparation process was optimized.In a 6-unit series connected battery,the efficiency of the module with an effective area of 10 cm² can reach 18.87%.