Premium
Importance of Optimal Crystallinity and Hole Mobility of BDT‐Based Polymer Donor for Simultaneous Enhancements of V oc , J sc , and FF in Efficient Nonfullerene Organic Solar Cells
Author(s) -
Park Jin Su,
Kim GeonU,
Lee Dongchan,
Lee Seungjin,
Ma Biwu,
Cho Shinuk,
Kim Bumjoon J.
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202005787
Subject(s) - crystallinity , materials science , electron mobility , acceptor , amorphous solid , energy conversion efficiency , polymer , homo/lumo , organic solar cell , open circuit voltage , side chain , halogen , crystallography , organic chemistry , optoelectronics , alkyl , chemistry , voltage , molecule , electrical engineering , physics , engineering , composite material , condensed matter physics
In this work, a new series of polymer donors consisting of thienothiophene π‐bridged N ‐octylthieno[3,4‐ c ]pyrrole‐4,6‐dione (8ttTPD) and benzo[1,2‐ b :4,5‐ b ']dithiophene (BDT) units for producing highly efficient organic solar cells (OSCs) paired with a Y6 acceptor is developed. The incorporation of the highly planar 8ttTPD unit enhances crystalline properties as well as hole mobilities of the BDT‐based polymers that typically have amorphous features. Further, the 2D side chains with halogen atoms (fluorine and chlorine) are designed as another handle to control the crystallinity and energy levels of the BDT‐based polymer donors: PBDT‐X (X = H, F, or Cl). Synergistic effects of incorporated 8ttTPD unit and the halogenated 2D side chain generate significantly enhanced charge transport and recombination properties of the OSCs, which is mainly attributed to optimized crystallinity and hole mobility of the polymer donors. Therefore, the PBDT‐Cl:Y6‐based OSCs exhibit the highest power conversion efficiency (PCE) of 15.63% with simultaneous improvements of open‐circuit voltage, short‐circuit current density, and fill factor, which outperforms the PCEs of PBDT‐H:Y6 (11.84%) and PBDT‐F:Y6 (14.86%).