Tuning the Molecular Weight of Chlorine-Substituted Polymer Donors for Small Energy Loss

• 作者: Tingxing Zhao Huan Wang Mingrui Pu Hanjian Lai Hui Chen Yulin Zhu Nan Zheng Feng He
• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Comprehensive Reports
• 页码范围: 1651-1658
• 页数: 8页
• 语种: 英文
• DOI: 10.1002/cjoc.202000735

摘要

Main observation and conclusion The molecular weight of polymers plays a major role in their aggregation and miscibility in active layer,which eventually dominate the energy loss and device performance.A series of chlorine-substituted PBD-Cl polymers with controlled molecular weight have been synthesized as templates to discern a relationship between molecular weight and the optical properties,energy levels,morphologies,energy loss and photovoltaic performance.Although it has similar optical and electrochemical properties,when blended with accep-tor N3,the low molecular weight polymer PBD-ClL gives the biggest energy loss value,and a PCE of 12.06％.PBD-ClH shows a moder-ate energy loss,but displays the lowest PCE of 9.00％as a result of excessive aggregation.PBD-ClM with a medium molecular weight gives the smallest energy loss and achieves a PCE of 17.17％,which is among one of the highest values recorded to date for the Cl-substituted polymer solar cells.Moreover,the molecular weight mainly affects the nonradiative energy loss(ΔE3),PBD-ClM also shows the smallest value of 0.252 eV among three polymer donors.These results show the effect of controlling the molecular weight to achieve a small energy loss and provide guidelines which can lead to an understanding of the real photovoltaic performance of new materials.