Zhang Qiang, Chen Zhenyu, Ma Wei, Xie Zhiyuan, Liu Jiangang, Yu Xinhong, Han Yanchun
State Key Laboratory of Polymer Physics and Chemistry , Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street , Changchun 130022 , China.
University of the Chinese Academy of Sciences , No. 19A Yuquan Road , Beijing 100049 , China.
ACS Appl Mater Interfaces. 2019 Sep 4;11(35):32200-32208. doi: 10.1021/acsami.9b06963. Epub 2019 Aug 23.
The rational design of the morphology of ternary all-polymer solar cells (all-PSCs) having broadened photon harvesting is crucial to achieve high device performance. However, multicomponent blends often illustrated an unfavorable morphology such as large-sized phase separation due to their complicated interaction. Herein, we proposed to solve these problems by employing two donors with good miscibility (J51 and PTB7-Th), which also have similar compatibility with the acceptor (N2200). The resultant ternary blend films of J51:PTB7-Th:N2200 feature a uniform phase separation morphology due to the reduced competitive effect of intermolecular interactions. As an additional polymer donor, PTB7-Th could not only enhance the absorption of the binary blend but also act as a crystallization regulator to boost the face-on orientation in ternary blends. Accordingly, the J51:PTB7-Th:N2200 ternary blends exhibited improved sunlight absorption and higher and well-balanced carrier mobility accompanied by enhanced carrier extraction. With the nonhalogenated cyclopentyl methyl ether as the processing solvent, the ternary all-PSCs showed outstanding power conversion efficiency (PCE) higher than 9% when varying the PTB7-Th weight ratio in donors from 20 to 50%. Due to the PTB7-Th content holding a 30% weight ratio in donors, the ternary all-PSCs demonstrated the optimal PCE of 9.60%, which perform better than those of binary all-PSCs (PCE = 7.58 or 5.63%).
合理设计具有拓宽光子捕获能力的三元全聚合物太阳能电池（全聚合物太阳能电池）的形态对于实现高器件性能至关重要。然而，多组分共混物由于其复杂的相互作用，常常呈现出不利的形态，如大尺寸相分离。在此，我们提出通过使用两种具有良好互溶性的供体（J51和PTB7-Th）来解决这些问题，它们与受体（N2200）也具有相似的相容性。由于分子间相互作用的竞争效应降低，所得的J51:PTB7-Th:N2200三元共混膜具有均匀的相分离形态。作为额外的聚合物供体，PTB7-Th不仅可以增强二元共混物的吸收，还可以作为结晶调节剂来促进三元共混物中的面内取向。因此，J51:PTB7-Th:N2200三元共混物表现出改善的太阳光吸收、更高且平衡的载流子迁移率以及增强的载流子提取。以非卤代环戊基甲基醚作为加工溶剂，当供体中PTB7-Th的重量比在20%至50%之间变化时，三元全聚合物太阳能电池表现出高于9%的出色功率转换效率（PCE）。由于供体中PTB7-Th的含量保持在30%的重量比，三元全聚合物太阳能电池表现出9.60%的最佳PCE，其性能优于二元全聚合物太阳能电池（PCE = 7.58或5.63%）。
