Delocalization of exciton and electron wavefunction in non-fullerene acceptor molecules enables efficient organic solar cells

A major challenge for organic solar cell (OSC) research is how to minimize the tradeoff between voltage loss and charge generation. In early 2019, we reported a non-fullerene acceptor (named Y6) that can simultaneously achieve high external quantum efficiency and low voltage loss for OSC. Here, we use a combination of experimental and theoretical modeling to reveal the structure-property-performance relationships of this state-of-the-art OSC system. We find that the distinctive π-π molecular packing of Y6 not only exists in molecular single crystals but also in thin films. Importantly, such molecular packing leads to (i) the formation of delocalized and emissive excitons that enable small non-radiative voltage…

• UO
  University of Arizona
• AN
  Australian Nuclear Science and Technology Organisation
• ST
  Solar Technologies go Hybrid

  Award: SFB 953
• AS
  Australian Synchrotron
• DF
  Deutsche Forschungsgemeinschaft

  Awards: 182849149, BR 4031/13-1
• NN
  National Natural Science Foundation of China

  Awards: 2017YFA0206600, 51903095, AoE/P-02/12, 2019B030302007, 2019YFA0705900
• MO
  Ministry of Science and Technology of the People's Republic of China

  Awards: 2017YFA0206600, 2019YFA0705900, AoE/P-02/12, No. 2017YFA0206600
• CP
  China Postdoctoral Science Foundation

  Awards: 2019M662906, 2019T120727, 2017M622681, 2017YFA0206600
• SC
  South China University of Technology
• SK
  State Key Laboratory of Luminescent Materials and Devices
• UN
  U.S. Navy

  Awards: N00014-20, N00014-20-1-2110
• FR
  Fundamental Research Funds for the Central Universities

  Awards: D2192160, 2017YFA0206600
• OO
  Office of Naval Research

  Awards: N00014-20-1-2110, N00014