合成新型氰基修饰的富勒烯衍生物降低介电失配实现高效反式钙钛矿太阳能电池  

Lowering the dielectric mismatch for efficient inverted perovskite solar cells through incorporating cyano-functionalized fullerene additive

作　　者：贾凌波 马鑫波 向文灏 江小芬 丁红鹤 李行成 商研渤 朱俊发 李震宇 邱永福 陈木青 陈江照 杨上峰 Lingbo Jia;Xinbo Ma;Wenhao Xiang;Xiaofen Jiang;Honghe Ding;Xingcheng Li;Yanbo Shang;Junfa Zhu;Zhenyu Li;Yongfu Qiu;Muqing Chen;Jiangzhao Chen;Shangfeng Yang(Hefei National Laboratory for Physical Sciences at Microscale,CAS Key Laboratory of Materials for Energy Conversion,Anhui Laboratory of Advanced Photon Science and Technology,Department of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China;School of Environment and Civil Engineering,Dongguan University of Technology,Dongguan 523808,China;Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China;National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China;Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education),College of Optoelectronic Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]Hefei National Laboratory for Physical Sciences at Microscale,CAS Key Laboratory of Materials for Energy Conversion,Anhui Laboratory of Advanced Photon Science and Technology,Department of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China [2]School of Environment and Civil Engineering,Dongguan University of Technology,Dongguan 523808,China [3]Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China [4]National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China [5]Key Laboratory of Optoelectronic Technology&Systems(Ministry of Education),College of Optoelectronic Engineering,Chongqing University,Chongqing 400044,China

出　　处：《Science China Materials》2023年第6期2146-2158,共13页中国科学（材料科学（英文版）

基　　金：partially supported by the National Natural Science Foundation of China(52172053,51925206,22272022,and U1932214)。

摘　　要：富勒烯衍生物,尤其是[1,1]苯基-C_(61)-丁酸-甲酯(PC_(61)BM),通常用作反式(p-i-n)钙钛矿太阳能电池(PVKSCs)的电子传输层和添加剂,但PC_(61)BM(3.8)的介电常数(ε_(r))远小于有机无机杂化铅卤钙钛矿(CH_(3)NH_(3)PbI_(3)[MAPbI_(3)]为6.5)的介电常数,不利于激子的解离且阻碍了界面电荷的传输.本文中,我们合成了一种新的氰基功能化富勒烯,其中两个氰基通过罗丹宁连接到富勒烯上(缩写为C_(60)-Rhd-CN),并通过反溶剂法将其引入MAPbI_(3)活性层中来构建反式钙钛矿太阳能电池器件.引入强吸电子氰基后,C_(60)-Rhd-CN的ε_(r)值达到5.1,明显高于PC_(61)BM(3.8),因此可以有效降低MAPbI_(3)钙钛矿和富勒烯电子传输层之间的介电失配.此外,氰基能够与MAPbI_(3)钙钛矿中的Pb^(2+)离子进行配位实现钙钛矿的缺陷钝化.最终,C_(60)-Rhd-CN掺入钙钛矿后促进了激子解离和界面电荷传输,并抑制了非辐射复合,使反式钙钛矿太阳能电池器件的能量转换效率从参比器件的18.43%显著提高到20.81%.此外,掺入C_(60)-Rhd-CN有助于提高钙钛矿太阳能电池的环境和热稳定性.为了阐明氰基在增加ε_(r)值和提高效率方面的关键作用,我们还合成了另一种类似结构的新型罗丹宁官能化富勒烯,其中两个氰基被硫原子取代(缩写为C_(60)-Rhd-S),其获得的能量转换效率为19.45%,其性能低于含有C_(60)-Rhd-CN添加剂的钙钛矿太阳能电池的主要原因是其ε_(r)值(4.0)较低.Fullerene derivatives especially[1,1]-phenyl-C_(61)-butyric-acid-methyl-ester(PC_(61)BM)have been commonly used as electron transport layers and additives of inverted(p-in)perovskite solar cells(PVKSCs);however the dielectric constant(ε_r)of PC_(61)BM(3.8)is much smaller than those of organolead halide hybrid perovskites(6.5 for CH_(3)NH_(3)PbI_(3)[MAPbI_(3)]),resulting in unfavorable exciton dissociation and impeded interfacial charge transport and consequently undesirable nonradiative recombination.Herein,a novel cyanofunctionalized fullerene in which two cyano groups are incorporated via a rhodanine moiety(abbreviated C_(60)-Rhd-CN)was synthesized and introduced into the MAPbI_(3)active layer to construct inverted PVKSCs via an anti-solvent method.The involvement of two electron-withdrawing cyano groups within C_(60)-Rhd-CN obviously increases theε_(r)value(5.1)relative to PC_(61)BM(3.8),hence lowering the dielectric mismatch between MAPbI_(3)and fullerene.Besides,the cyano groups enable strong coordination interactions with the Pb^(2+)ions of MAPbI_(3),rendering efficient defect passivation of perovskite.As a result,C_(60)-Rhd-CN incorporation facilitates exciton dissociation and interfacial charge transport and suppresses the nonradiative recombination,affording dramatic power conversion efficiency(PCE)enhancement of inverted PVKSC devices from 18.43%to 20.81%.Furthermore,C_(60)-Rhd-CN incorporation helps to improve the ambient and thermal stabilities of PVKSC devices.To elucidate the critical role of cyano groups in increasing theε_(r)value and efficiency enhancement,another analogous novel rhodanine-functionalized fullerene with the two cyano groups substituted by a sulfur atom(abbreviated C_(60)-Rhd-S)was also synthesized,which delivered a lower PCE of 19.45%than C_(60)-Rhd-CN-incorporated devices due mainly to its lowerε_(r)value(4.0).

关 键 词：钙钛矿太阳能电池 能量转换效率 富勒烯衍生物 介电常数 电子传输层 非辐射复合 失配 硫原子 

分 类 号：TB34[一般工业技术—材料科学与工程] TM914.4[电气工程—电力电子与电力传动]