Preparation And Research Of Efficient And Stable Perovskite Solar Cell

With the increasingly serious global warming effect,people urgently want to find new clean energy to replace fossil energy to solve the problem of global warming.The most abundant clean energy in the world is solar energy,and solar cells are one of the effective ways to develop and utilize solar energy.Perovskite solar cells（PSCs）are the third generation of new solar cells,and they have become a new star in photovoltaic power generation due to their ultra-high absorption coefficient,environmentally friendly and cheap raw materials and simple spin-coating process.However,to achieve commercialization of perovskite solar cells,the photoelectric conversion efficiency（PCE）and stability issues still need to be further improved.In this paper,the electron extraction at the interface is improved by regulating the electron transport layer（ETL）and the hysteresis is reduced;a novel pure inorganic two-dimensional（2D）perovskite material is prepared to improve the stability of PSCs;2D material is used to passivate the surface of FAPbI₃film vacancy defects,improve hole extraction rate,reduce non-radiative recombination and inhibit ion migration,and finally prepare efficient and stable PSCs devices.The main research results are as follows:（1）By optimizing the concentration of the electron transport layer and doping cobalt salts into the ETL,it is proposed to improve the electron extraction at the interface between the electron transport layer and the perovskite absorber layer and the quality of the perovskite film.Finally,the optimal PCE of 19.97%was obtained at the doping amount of FK209 and titanium diisopropoxybisacetylacetonate with a molar ratio of 1:1000.Under the same conditions,the initial efficiency is only 17.70%,the device has serious hysteresis and poor stability.（2）The two-dimensional perovskite with n=1 was prepared by replacing the R-site ions of the two-dimensional perovskite R₂A_n-1B_nX_3n+1with（Ca Br）⁺and（Mg Br）⁺composed of alkaline earth metals and halide ions.materials,and prepared two-dimensional perovskite solar cells with n=20,40,and 60,respectively.In this paper,the stability of maintaining more than 95%of the initial efficiency after 1000 h was obtained,but the highest PCE was only18.43%.（3）By passivating the FAPbI₃perovskite with the newly prepared two-dimensional perovskite material,the vacancy defects on the surface of the three-dimensional perovskite film are passivated and the non-radiative recombination is reduced to improve the battery PCE;The strong ionic polarization of metal ions on halide ions to suppress ion migration improves the stability of perovskite solar cell devices.Finally,an optimal PCE of 23.08%was obtained,and the stability of the device remained more than 90%of the initial efficiency after 1000 h.