Lai Hanjian, Chen Hui, Zhou Jiadong, Qu Jianfei, Chao Pengjie, Liu Tao, Chang Xiaoyong, Zheng Nan, Xie Zengqi, He Feng
Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen 518055, China; School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen 518055, China.
iScience. 2019 Jul 26;17:302-314. doi: 10.1016/j.isci.2019.06.033. Epub 2019 Jun 28.
The influence caused by the position of the chlorine atom on end groups of two non-fullerene acceptors (ITIC-2Cl-δ and ITIC-2Cl-γ) was intensely investigated. The single-crystal structures show that ITIC-2Cl-γ has a better molecular planarity and closer π-π interaction distance. More importantly, a 3D rectangle-like interpenetrating network is formed in ITIC-2Cl-γ and is beneficial to rapid charge transfer along multiple directions, whereas only a linear stacked structure could be observed in ITIC-2Cl-δ. The two acceptor-based solar cells show power conversion efficiencies (PCEs) over 11%, higher than that of the ITIC-2Cl-m-based device (10.85%). An excellent PCE of 13.03% is obtained by the ITIC-2Cl-γ-based device. In addition, the ITIC-2Cl-γ-based device also shows the best device stability. This study indicates that chlorine positioning has a great impact on the acceptors; more importantly, the 3D network structure may be a promising strategy for non-fullerene acceptors to improve the PCE and stability of organic solar cells.
深入研究了氯原子在两种非富勒烯受体（ITIC-2Cl-δ和ITIC-2Cl-γ）端基上的位置所产生的影响。单晶结构表明，ITIC-2Cl-γ具有更好的分子平面性和更近的π-π相互作用距离。更重要的是，ITIC-2Cl-γ中形成了三维矩形互穿网络，有利于电荷沿多个方向快速转移，而在ITIC-2Cl-δ中只能观察到线性堆积结构。这两种基于受体的太阳能电池的功率转换效率（PCE）超过11%，高于基于ITIC-2Cl-m的器件（10.85%）。基于ITIC-2Cl-γ的器件获得了13.03%的优异PCE。此外，基于ITIC-2Cl-γ的器件还表现出最佳的器件稳定性。这项研究表明，氯的定位对受体有很大影响；更重要的是，三维网络结构可能是一种有前途的策略，用于非富勒烯受体提高有机太阳能电池的PCE和稳定性。
