Open AccessAn Optimized Fibril Network Morphology Enables High‐Efficiency and Ambient‐Stable Polymer Solar Cells
Author(s) -
Song Jiali,
Ye Linglong,
Li Chao,
Xu Jinqiu,
Chandrabose Sreelakshmi,
Weng Kangkang,
Cai Yunhao,
Xie Yuanpeng,
O'Reilly Padraic,
Chen Kai,
Zhou Jiajia,
Zhou Yi,
Hodgkiss Justin M.,
Liu Feng,
Sun Yanming
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202001986
Subject(s) - morphology (biology) , materials science , fibril , polymer , nanotechnology , chemical engineering , biophysics , composite material , geology , engineering , biology , paleontology
Morphological stability is crucially important for the long‐term stability of polymer solar cells (PSCs). Many high‐efficiency PSCs suffer from metastable morphology, resulting in severe device degradation. Here, a series of copolymers is developed by manipulating the content of chlorinated benzodithiophene‐4,8‐dione (T1‐Cl) via a random copolymerization approach. It is found that all the copolymers can self‐assemble into a fibril nanostructure in films. By altering the T1‐Cl content, the polymer crystallinity and fibril width can be effectively controlled. When blended with several nonfullerene acceptors, such as TTPTT‐4F, O‐INIC3, EH‐INIC3, and Y6, the optimized fibril interpenetrating morphology can not only favor charge transport, but also inhibit the unfavorable molecular diffusion and aggregation in active layers, leading to excellent morphological stability. The work demonstrates the importance of optimization of fibril network morphology in realizing high‐efficiency and ambient‐stable PSCs, and also provides new insights into the effect of chemical structure on the fibril network morphology and photovoltaic performance of PSCs.