A rational design of efficient low-band-gap non-fullerene acceptors (NFAs) for high-performance organic solar cells (OSCs) remains challenging;the main constraint being the decrease in the energy level of the lowest unoccupied molecular orbitals (LUMOs) as the bandgap of A-D-A-type NFAs decrease.Therefore,the short current density (Jsc) and open-circuit voltage (Voc) result in a trade-off relationship,making it difficult to obtain efficient OSCs.Herein,three NFAs (IFL-ED-4F,IDT-ED-4F,and IDTT-ED-2F) were synthe-sized to address the above-mentioned issue by introducing 3,4-ethylenedioxythiophene (EDOT) as a n-bridge.These NFAs exhibit relatively low bandgaps (1.67,1.42,and 1.49 eV,respectively) and upshifted LUMO levels (-3.88,-3.84,and-3.81 eV,respectively) compared with most reported low-band-gap NFAs.Consequently,the photovoltaic devices based on IDT-ED-4F blended with a PBDB-T donor polymer showed the best power conversion efficiency (PCE) of 10.4％ with a high Jsc of 22.1 mA cm-2 and Voc of 0.884 V among the examined NFAs.In contrast,IDTIT-ED-4F,which was designed with an asymmetric structure of the D-π-A type,showed the lowest efficiency of 1.5％ owing to the poor morphology and charge transport properties of the binary blend.However,when this was introduced as the third compo-nent of the PM6:BTP-BO-4Cl,complementary absorption and cascade energy-level alignment between the two substances could be achieved.Surprisingly,the IDTT-ED-4F-based ternary blend device not only improved the Jsc and Voo but also achieved a PCE of 15.2％,which is approximately 5.3％ higher than that of the reference device with a minimized energy loss of 0.488 eV.In addition,the universality of IDTT-ED-2F as a third component was effectively demonstrated in other photoactive systems,specifically,PM6:BTP-eC9 and PTB7-Th:IEICO-4F.This work facilitates a better understanding of the structure-property rela-tionship for utilizing efficient EDOT-bridged NFAs in high-performance OSC applications.

Sung Jae Jeon;Young Hoon Kim;Ie Na Kim;Nam Gyu Yang;Ji Hee Yun;Doo Kyung Moon

Nano and Information Materials (NIMs) Laboratory,Department of Chemical Engineering,Konkuk University,120 Neungdong-ro Gwangjin-gu,Seoul 05029,South Korea;Department of Academy of Applied Science and Technology,Konkuk University,120 Neungdong-ro Gwangjin-gu,Seoul 05029,South Korea

能源化学

[1]Sung Jae Jeon;Young Hoon Kim;Ie Na Kim;Nam Gyu Yang;Ji Hee Yun;Doo Kyung Moon-.Utilizing 3,4-ethylenedioxythiophene (EDOT)-bridged non-fullerene acceptors for efficient organic solar cells)[J].能源化学,2022(02):194-204

LUMOs,IFL,IDTT,IDTIT,Voo,IEICO

Utilizing,ethylenedioxythiophene,EDOT,bridged,fullerene,acceptors,efficient,organic,solar,cells,rational,NFAs,performance,OSCs,remains,challenging,constraint,being,decrease,energy,lowest,unoccupied,molecular,orbitals,type,Therefore,short,current,density,Jsc,open,circuit,voltage,Voc,result,trade,off,relationship,making,difficult,obtain,Herein,three,4F,2F,were,synthe,sized,address,above,mentioned,issue,by,introducing,These,exhibit,relatively,bandgaps,eV,respectively,upshifted,levels,compared,most,reported,Consequently,photovoltaic,devices,blended,PBDB,donor,polymer,showed,best,power,conversion,efficiency,PCE,mA,among,examined,In,contrast,which,was,designed,asymmetric,structure,owing,poor,morphology,charge,transport,properties,binary,However,when,this,introduced,third,PM6,BTP,BO,4Cl,complementary,absorption,cascade,alignment,between,two,substances,could,achieved,Surprisingly,ternary,not,only,improved,but,also,approximately,higher,than,that,reference,minimized,loss,addition,universality,component,effectively,demonstrated,other,photoactive,systems,specifically,eC9,PTB7,This,work,facilitates,better,understanding,property,utilizing,applications

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