While serious stability issues impede the commercialization of perovskite solar cells (PSCs),two-dimensional (2D) perovskites based on fluorinated bulky cations have emerged as more intrinsically stable materials.However,the influence of fluorination degree of the bulky aromatic cation on the per-formance of resulting PSCs has not been scrutinized.Here,2D perovskites (FxPEA)2PbI4 (x =1,2,3,5) are grown in situ on the surface of the three-dimensional (3D) perovskite and demonstrate effective passiva-tion of the surface defects of 3D perovskite.The power conversion efficiency (PCE) of the optimized devices were boosted from 20.75％ for the control device to 21.09％,22.06％,22.74％ and 21.86％ for 2D/BD devices treated with 4-fluorophenethylamine iodide,3,5-difluorophenylethylamine iodide,2,4,5-trifluoroethylphenylethylamine iodide,and 1,2,3,4,5-pentafluorophenylethylamine iodide,respec-tively.We firstly reported two unexplored RP-type layered perovskites with F2PEAI and F3PEAI as bulky cations.The combined experimental and theoretical analysis revealed the reasons behind the various morphology,device performances,dynamic behavior,and humidity stability.The best performing FsPEAl-treated device retaining 95.0％ of its initial PCE under ambient atmosphere (with RH of 60％ ± 5％) without encapsulation for 300 h storage.This work provides useful guidance for selecting flu-orinated bulky cations with different molecular electronic properties,which will play an essential role in further improving the performance/stability of PSCs for the sake of further commercialization.

Lei Wang;Qin Zhou;Zilong Zhang;Wenbo Li;Xiaobing Wang;Qing Tian;Xiaoyan Yu;Ting Sun;Jihuai Wu;Bao Zhang;Peng Gao

School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China;CAS Key Laboratory of Design and Assembly of Functional Nanostructures,and Fujian Provincial Key Laboratory of Nanomaterials,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,Fujian,China;Laboratory for Advanced functional Materials,Xiamen Institute of Rare Earth Materials,Haixi Institute,Chinese Academy of Sciences,Xiamen 361021,Fujian,China;College of Materials Science and Engineering,Huaqiao University,361021 Xiamen,Fujian,China

能源化学

[1]Lei Wang;Qin Zhou;Zilong Zhang;Wenbo Li;Xiaobing Wang;Qing Tian;Xiaoyan Yu;Ting Sun;Jihuai Wu;Bao Zhang;Peng Gao-.A guide to use fluorinated aromatic bulky cations for stable and high-performance 2D/3D perovskite solar cells:The more fluorination the better?)[J].能源化学,2022(01):179-189

FxPEA,fluorophenethylamine,difluorophenylethylamine,trifluoroethylphenylethylamine,pentafluorophenylethylamine,F2PEAI,F3PEAI,FsPEAl,orinated

guide,fluorinated,aromatic,bulky,cations,stable,high,2D,solar,cells,more,fluorination,better,While,serious,stability,issues,impede,commercialization,PSCs,two,dimensional,perovskites,have,emerged,intrinsically,materials,However,influence,degree,resulting,has,not,been,scrutinized,Here,2PbI4,are,grown,situ,surface,three,demonstrate,effective,passiva,defects,power,conversion,efficiency,PCE,optimized,devices,were,boosted,from,control,BD,treated,iodide,respec,tively,We,firstly,reported,unexplored,RP,type,layered,combined,experimental,theoretical,analysis,revealed,reasons,behind,various,morphology,performances,dynamic,behavior,humidity,best,performing,retaining,its,initial,under,ambient,atmosphere,RH,without,encapsulation,storage,This,work,provides,useful,guidance,selecting,different,molecular,electronic,properties,which,will,play,essential,role,further,improving,sake

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