Chemical Chelation-assisted Highly Oriented Perovskitebased Solar Cells With Reduced Non-radiative Recombination

In recent years,perovskite photovoltaic devices have developed rapidly,and the photoelectric conversion efficiency has been significantly improved:the efficiency of single-junction perovskite devices has reached 25.7%,and the efficiency of laminated devices has broken through 30%.The efficiency of perovskite photovoltaic devices is comparable to that of commercial silicon solar cells.However,due to poor stability and incomplete film preparation strategy,the industrial production of perovskite photovoltaic devices has not been realized.Among the common device performance improvement strategies,additives and surface passivating agents are widely used and have universal applicability,which is an effective optimization strategy.However,the selection of surface and bulk phase modifiers is mostly based on the experimental and theoretical experience of researchers to judge whether organic molecules,polymers or inorganic compounds can play the role of passivation defects in the internal and interface of perovskite films,so as to improve the efficiency and stability of devices.The above selection methods of modifiers are more dependent on randomness and can not completely form the experience summary system or specific theoretical basis for the selection of modifiers.Therefore,the current research on the modification system of perovskite devices is more inclined to the non-related multi-point scattered form,and there is still a long way to go before the formation of the"system tree"model which is connected with each other and connects the past and the future.By introducing the soft and hard acid base theory,this study hopes to expand the selection vision and theoretical application scope of perovskite device modifiers,provide a new thinking Angle for the future development of perovskite modifiers,and lay a foundation for the formation and development of the theoretical system of perovskite modifiers.In this paper,2,5-Furandicarboxylic acid（FDCA）molecules were doped into perovskite photovoltaic devices as thin film modifier,and different preparation methods were explored to improve the efficiency of the devices.By comparing the efficiency statistical distribution of the device optimization stage,it can be concluded that 0.1 mg/ml is the best precursor doping concentration.The performance of electron transport layer prepared by Sn O₂colloidal solution dilution method with IPA participating in dilution is better.Perovskite film containing FDCA concentration of 0.1 mg/ml was prepared in the follow-up experiment and characterization for relevant tests.According to the device performance and film characterization results,FDCA can interact with Pb²⁺,I^-,FA⁺and other components of perovskite film,inhibit ion migration and improve the crystal quality of perovskite film.Carrier transmission is improved accordingly;Density functional theory calculation assisted to prove that FDCA anchored ions in perovskite films and reduced defect density.Finally,the efficiency of FDCA modified device is improved to 24.07%,and the open-circuit voltage is up to 1.209 V.The air stability of the device is obviously improved,and the device can still maintain 83%of the initial efficiency value after more than 1600 hours of placement.