In:
Advanced Energy Materials, Wiley, Vol. 11, No. 47 ( 2021-12)
Abstract:
Fluorination of the donor and/or acceptor blocks of photoactive semiconducting polymers is a leading strategy to enhance organic solar cell (OSC) performance. Here, the effects are investigated in OSCs using fluorine‐free ( TPD‐3 ) and fluorinated ( TPD‐3F ) donor polymers, paired with the nonfullerene acceptor Y6. Interestingly and unexpectedly, fluorination negatively affects performance, and fluorine‐free TPD‐3 :Y6 OSCs exhibit a far higher power conversion efficiency (PCE = 14.5%) than in the fluorine‐containing TPD‐3F :Y6 blends (PCE = 11.5%). Transmission electron microscopy (TEM) analysis indicates that the TPD‐3F :Y6 blends have larger phase domain sizes than TPD‐3 :Y6, which reduces exciton dissociation efficiency to 81% for TPD‐3F :Y6 versus 93% for TPD‐3 :Y6. Additionally, grazing incidence wide‐angle X‐ray scattering (GIWAXS) reveals that the TPD‐3F :Y6 blends are less textured than those of TPD‐3 :Y6, while space‐charge limited currents reveal lower and unbalanced hole/electron mobility in TPD‐3F :Y6 versus TPD‐3 :Y6 blends. Charge recombination dynamic, transient absorption, and donor–acceptor miscibility assays additionally support this picture. Furthermore, conventional architecture TPD‐3 :Y6 OSCs deliver a PCE of 15.2%, among the highest to date for halogen‐free polymer donor OSCs. Finally, a large‐area (20.4 cm 2 ) TPD‐3 :Y6 blend module exhibits an outstanding PCE of 9.31%, one of the highest to date for modules of area 〉 20 cm 2 .
Type of Medium:
Online Resource
ISSN:
1614-6832
,
1614-6840
DOI:
10.1002/aenm.202102648
Language:
English
Publisher:
Wiley
Publication Date:
2021
detail.hit.zdb_id:
2594556-7
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