The replacement of small cations with bulkier organic cations containing long alkyl chains or benzene rings to form a thin two-dimensional (2D) perovskite passivation layer on three-dimensional (3D) per-ovskite (2D/3D) has become a promising strategy for improving both the efficiency and stability of per-ovskite solar cells (PSCs).The 2D layer defines the interfacial chemistry and physics at the 2D/3D bilayer and endows the 2D/3D structure with better chemical and thermal stability.Herein,2D/3D (CF3-PEA)2FA0.85MA0.15Pb2I7/FA0.85MA0.15PbI3 planar heterojunction perovskite was produced using a facile interfacial ion exchange process.The 2D (CF3-PEA)2FA0.85MA0.15Pb2I7 capping layer can not only passivate the FA0.85MA0.15Pbl3 film but also act as super-hydrophobic layer to inhibit water diffusion and signifi-cantly enhance the stability.The 2D capping layer can also establish a unique graded band structure at the perovskite/Spiro-OMeTAD interface and lead to p-type doping for Spiro-OMeTAD layer which is ben-eficial for efficient charge transport.Optimized PSCs based on this 2D/3D heterojunction yield a cham-pion power conversion efficiency (PCE) of 23.1％ and improved stability.The device maintains 84％output for 2400 h aging under ambient environmental conditions without encapsulation,and maintains 81％ for 200 h under illumination with encapsulation,This work will inspire the design of more fluori-nated 2D perovskite interfaces for advanced photovoltaics and beyond.

Yuan Cai;Jialun Wen;Zhike Liu;Fang Qian;Chenyang Duan;Kun He;Wenjing Zhao;Sheng Zhan;Shaomin Yang;Jian Cui;Shengzhong Liu

Key Laboratory of Applied Surface and Colloid Chemistry,Ministry of Education,Shaanxi Key Laboratory for Advanced Energy Devices,Shaanxi Engineering Lab for Advanced Energy Technology,School of Materials Science and Engineering,Shaanxi Normal University,Xi'an 710119,Shaanxi,China;iChEM,Dalian Institute of Chemical Physics,University of Chinese Academy of Sciences,Dalian National Laboratory for Clean Energy,Chinese Academy of Sciences,Dalian 116023,Liaoning,China

能源化学

[1]Yuan Cai;Jialun Wen;Zhike Liu;Fang Qian;Chenyang Duan;Kun He;Wenjing Zhao;Sheng Zhan;Shaomin Yang;Jian Cui;Shengzhong Liu-.Graded 2D/3D (CF3-PEA)2FA0.85MA0.15Pb2I7/FA0.85MA0.15PbI3 heterojunction for stable perovskite solar cell with an efficiency over 23.0％)[J].能源化学,2022(02):480-489

2FA0,85MA0,15Pb2I7,15PbI3,bulkier,15Pbl3,fluori

Graded,2D,CF3,PEA,heterojunction,stable,perovskite,solar,efficiency,over,replacement,small,cations,organic,containing,long,alkyl,chains,benzene,rings,form,thin,two,dimensional,passivation,three,has,become,promising,strategy,improving,both,stability,cells,PSCs,defines,interfacial,chemistry,physics,bilayer,endows,structure,better,chemical,thermal,Herein,planar,was,produced,using,facile,exchange,process,capping,not,only,passivate,film,but,also,act,super,hydrophobic,inhibit,water,diffusion,signifi,cantly,enhance,establish,unique,graded,band,Spiro,OMeTAD,lead,type,doping,which,eficial,efficient,charge,transport,Optimized,this,yield,cham,pion,power,conversion,PCE,improved,device,maintains,output,aging,under,ambient,environmental,conditions,without,encapsulation,illumination,This,work,will,inspire,design,more,nated,interfaces,advanced,photovoltaics,beyond

0.4957