Pyrene-Based Dopant-Free Hole-Transport Polymers with Fluorine-Induced Favorable Molecular Stacking Enable Efficient Perovskite Solar Cells
  
  
 
 
  
   
    By:
    Yao, ZY (Yao, Zhaoyang) [1] , [2] ; 
    Zhang, FG (Zhang, Fuguo) [2] ; 
    He, LL (He, Lanlan) [3] ; 
    Bi, XQ (Bi, Xingqi) [1] ; 
    Guo, YX (Guo, Yaxiao) [2] , [4] ; 
    Guo, Y (Guo, Yu) [5] ; 
    Wang, LQ (Wang, Linqin) [5] ; 
    Wan, XJ (Wan, Xiangjian) [1] ; 
    Chen, YS (Chen, Yongsheng) [1] ; 
    Sun, LC (Sun, Licheng) [2] , [5]
    
   
 
 
 
 
  
DOI
  10.1002/anie.202201847
 
 
  
 
 
 
 
  Abstract
  
   
    A new class of polymeric hole-transport materials (HTMs) are explored by inserting a two-dimensionally conjugated fluoro-substituted pyrene into thiophene and selenophene polymeric chains. The broad conjugated plane of pyrene and "Lewis soft" selenium atoms not only enhance the pi-pi stacking of HTM molecules greatly but also render a strong interaction with the perovskite surface, leading to an efficient charge transport/transfer in both the HTM layer and the perovskite/HTM interface. Note that fluorine substitution adjacent to pyrene boosts the stacking of HTMs towards a more favorable face-on orientation, further facilitating the efficient charge transport. As a result, perovskite solar cells (PSCs) employing PE10 as dopant-free HTM afford an excellent efficiency of 22.3 % and the dramatically enhanced device longevity, qualifying it among the best PSCs based on dopant-free HTMs.