摘要
With recent advances in the power conversion efficiency(PCE)of organic solar cells(OSCs)based on novel donor and non-fullerene acceptor(NFAs),improving the stability of these systems has become the most important issue for their practical applications.Herein,an efficient and highly stable OSC,containing a novel polymer donor and a non-fullerene acceptor system,is reported.The OSC is based on an inverted device structure that utilizes a self-assembled fullerene monolayer(C60-SAM)as the cathode modification layer,and an efficient and highly stable OSC composes of a polymer donor of poly[4,8-bis(5-(2-ethyl hexyl)thiophen-2-yl)benzo[1,2-b:4,5-b’]dithiophene-alt-3-fluorothie-no[3,4-b]thiophene-2-c arboxylate](PTB7-Th)and a non-fullerene acceptor of(2,2’-((2 Z,2’Z)-(((4,4,9,9-Tetrakis(4-hexylphenyl)-4,9-dihydro-sindaceno[1,2-b:5,6-b’]dithiophene-2,7-diyl)bis(4-((2 ethylhexyl)oxy)thiophene-5,2-diyl))bis(metha nylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-l H-indene-2,1-diylidene))dimalononitrile)(IEICO-4 F)is presented,showing a PCE of 10%.It further achieves an extrapolated T80 lifetime(the time required to reach 80%of initial performance)of 34,000 h,operating under one sun illumination equivalent Based on an estimated solar irradiance of 1500 kWh/(m2 year)for China,a potential lifetime of22 years is inferred for the OSC.Further investigation reveals that the reported C60-SAM modification stabilizes the OSC active layer morphology by lowering the surface energy of the underlying ZnO electron transport layer and suppressing trap-assisted recombination,thereby improving photostability.The results of this work establish important guidelines for the development of non-fullerene based OSCs with enhanced stability and pave the way for the commercialization of OSC technology.
近年来,由于新型非富勒烯受体材料的快速发展,诸多中国科学家在有机太阳电池(OPV)的能量转换效率(PCE)上取得了重大突破.为了实现OPV的产业化,目前亟待解决的难题在于提升OPV的使用寿命,并降低大面积模组器件的效率滚降.本文提出了一种简易而有效的阴极界面修饰方法,成功实现了非富勒烯有机太阳电池超过20年的使用寿命.文章采用自组装小分子C60-SAM对氧化锌阴极界面进行修饰,不仅可以调控氧化锌和活性层之间的表面能匹配及其分子间相互作用来得到形貌更稳定的器件,同时还能通过钝化氧化锌表面缺陷以提升电池器件的电荷抽取效率.在此基础上,作者基于PTB7-Th:IEICO-4F制备得到PCE=10%,持续光照下寿命长达34000 h的OPV器件.根据中国平均每年1500 kWh/m2太阳辐射量推算,该OPV器件的使用寿命可超过20年.这将为OPV技术实现商业化带来极强曙光.
作者
Xiang Xu
Jingyang Xiao
Guichuan Zhang
Long Wei
Xuechen Jiao
Hin-Lap Yip
Yong Cao
徐翔;肖经洋;张桂传;韦拢;焦学琛;叶轩立;曹镛(State Key Laboratory of Luminescent Materials and Devices,Institute of Polymer Optoelectronic Materials and Devices,School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China;Innovation Center of Printed Photovoltaics,South China Institute of Collaborative Innovation,Dongguan 523808,China;Department of Materials Science and Engineering,Monash University,Victoria 3800,Australia;Australian Synchrotron,ANSTO,Clayton,Victoria 3168,Australia)
基金
financially supported by the National Key Research and Development Program of China(2017YFA0206600)
the National Natural Science Foundation of China(21761132001,91633301,51573057,and 51903095)
the Fundamental Research Funds for the Central Universities(D2192160)
performed in part on the SAXS/WAXS beamline at the Australian Synchrotron,which is part of the ANSTO.
