Simultaneously Achieving Highly Efficient and Stable Polymer:Non-Fullerene Solar Cells Enabled By Molecular Structure Optimization and Surface Passivation

Bowen Liu, Xiao Su, Yi Lin, Zerui Li, Lingpeng Yan, Yunfei Han, Qun Luo*, Jin Fang, Shangfeng Yang, Hongwei Tan*, Chang Qi Ma*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Despite the tremendous efforts in developing non-fullerene acceptor (NFA) for polymer solar cells (PSCs), only few researches are done on studying the NFA molecular structure dependent stability of PSCs, and long-term stable PSCs are only reported for the cells with low efficiency. Herein, the authors compare the stability of inverted PM6:NFA solar cells using ITIC, IT-4F, Y6, and N3 as the NFA, and a decay rate order of IT-4F > Y6 ≈ N3 > ITIC is measured. Quantum chemical calculations reveal that fluorine substitution weakens the C═C bond and enhances the interaction between NFA and ZnO, whereas the β-alkyl chains on the thiophene unit next to the C═C linker blocks the attacking of hydroxyl radicals onto the C═C bonds. Knowing this, the authors choose a bulky alkyl side chain containing molecule (named L8-BO) as the acceptor, which shows slower photo bleaching and performance decay rates. A combination of ZnO surface passivation with phenylethanethiol (PET) yields a high efficiency of 17% and an estimated long T80 and Ts80 of 5140 and 6170 h, respectively. The results indicate functionalization of the β-position of the thiophene unit is an effective way to improve device stability of the NFA.

Original languageEnglish
Article number2104588
JournalAdvanced Science
Issue number7
Publication statusPublished - 4 Mar 2022


  • degradation and stability
  • interfacial photon decomposition
  • non-fullerene acceptor
  • polymer solar cells
  • structure-property relationship

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