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Mechanistic Investigation into Dynamic Function of Third-Component Incorporated in Ternary Near-Infrared Nonfullerene Organic Solar Cells

Wang, Zhuoyan ; Ji, Jingjing ; Lin, Weihua LU ; Yao, Yao ; Zheng, Kaibo LU and Liang, Ziqi (2020) In Advanced Functional Materials 30(31).
Abstract

Organic solar cells (OSCs) consisting of an ultralow-bandgap nonfullerene acceptor (NFA) with an optical absorption edge that extends to the near-infrared (NIR) region are of vital interest to semitransparent and tandem devices. However, huge energy-loss related to inefficient charge dissociation hinders their further development. The critical issues of charge separation as exemplified in NIR-NFA OSCs based on the paradigm blend of PTB7–Th donor (D) and IEICO–4F acceptor (A) are revealed here. These studies corroborate efficient charge transfer between D and A, accompanied by geminate recombination of photo-excited charge carriers. Two key factors restricting charge separation are unveiled as the connection discontinuity of individual... (More)

Organic solar cells (OSCs) consisting of an ultralow-bandgap nonfullerene acceptor (NFA) with an optical absorption edge that extends to the near-infrared (NIR) region are of vital interest to semitransparent and tandem devices. However, huge energy-loss related to inefficient charge dissociation hinders their further development. The critical issues of charge separation as exemplified in NIR-NFA OSCs based on the paradigm blend of PTB7–Th donor (D) and IEICO–4F acceptor (A) are revealed here. These studies corroborate efficient charge transfer between D and A, accompanied by geminate recombination of photo-excited charge carriers. Two key factors restricting charge separation are unveiled as the connection discontinuity of individual phases in the blend and long-lived interfacial charge-transfer states (CTS). By incorporation of a third-component of benchmark ITIC or PC71BM with various molar ratios, these two issues are well-resolved accordingly, yet in distinctly influencing mechanisms. ITIC molecules modulate film morphology to create more continuous paths for charge transportation, whereas PC71BM diminishes CTS and enhances electron transfer at the D/A interfaces. Consequently, the optimal untreated ternary OSCs comprising 0.3 wt% ITIC and 0.1 wt% PC71BM in the blend deliver higher JSC values of 21.9 and 25.4 mA cm-2, and hence increased PCE of 10.2% and 10.6%, respectively.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
charge and energy transfer, charge recombination, near-infrared, nonfullerene acceptors, organic solar cells
in
Advanced Functional Materials
volume
30
issue
31
article number
2001564
publisher
Wiley-Blackwell
external identifiers
  • scopus:85086176523
ISSN
1616-301X
DOI
10.1002/adfm.202001564
language
English
LU publication?
yes
id
61a2bdee-e56a-40ab-bb87-48be95554728
date added to LUP
2020-07-02 16:33:51
date last changed
2023-11-20 07:20:34
@article{61a2bdee-e56a-40ab-bb87-48be95554728,
  abstract     = {{<p>Organic solar cells (OSCs) consisting of an ultralow-bandgap nonfullerene acceptor (NFA) with an optical absorption edge that extends to the near-infrared (NIR) region are of vital interest to semitransparent and tandem devices. However, huge energy-loss related to inefficient charge dissociation hinders their further development. The critical issues of charge separation as exemplified in NIR-NFA OSCs based on the paradigm blend of PTB7–Th donor (D) and IEICO–4F acceptor (A) are revealed here. These studies corroborate efficient charge transfer between D and A, accompanied by geminate recombination of photo-excited charge carriers. Two key factors restricting charge separation are unveiled as the connection discontinuity of individual phases in the blend and long-lived interfacial charge-transfer states (CTS). By incorporation of a third-component of benchmark ITIC or PC<sub>71</sub>BM with various molar ratios, these two issues are well-resolved accordingly, yet in distinctly influencing mechanisms. ITIC molecules modulate film morphology to create more continuous paths for charge transportation, whereas PC<sub>71</sub>BM diminishes CTS and enhances electron transfer at the D/A interfaces. Consequently, the optimal untreated ternary OSCs comprising 0.3 wt% ITIC and 0.1 wt% PC<sub>71</sub>BM in the blend deliver higher J<sub>SC</sub> values of 21.9 and 25.4 mA cm<sup>-2</sup>, and hence increased PCE of 10.2% and 10.6%, respectively.</p>}},
  author       = {{Wang, Zhuoyan and Ji, Jingjing and Lin, Weihua and Yao, Yao and Zheng, Kaibo and Liang, Ziqi}},
  issn         = {{1616-301X}},
  keywords     = {{charge and energy transfer; charge recombination; near-infrared; nonfullerene acceptors; organic solar cells}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{31}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Advanced Functional Materials}},
  title        = {{Mechanistic Investigation into Dynamic Function of Third-Component Incorporated in Ternary Near-Infrared Nonfullerene Organic Solar Cells}},
  url          = {{http://dx.doi.org/10.1002/adfm.202001564}},
  doi          = {{10.1002/adfm.202001564}},
  volume       = {{30}},
  year         = {{2020}},
}