iScience
Volume 17, 26 July 2019, Pages 302-314
Journal home page for iScience

Article
Isomer-free: Precise Positioning of Chlorine-Induced Interpenetrating Charge Transfer for Elevated Solar Conversion

https://doi.org/10.1016/j.isci.2019.06.033Get rights and content
Under a Creative Commons license
open access

Highlights

  • Isomer-free: improved phase purity for high-performance non-fullerene acceptor

  • Chlorine-substitution fine-tuned the configurations and properties of molecules

  • Precise Cl-atom substitution induced 3D interpenetrating network charge transfer

  • ITIC-2Cl-γ exhibited higher PCE of 13.03% and better stability

Summary

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.

Subject Areas

Energy Storage
Chemical Synthesis
Materials Characterization Techniques

Cited by (0)

4

These authors contributed equally

5

Lead Contact