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Unveiling Excitonic Dynamics in High-Efficiency Nonfullerene Organic Solar Cells to Direct Morphological Optimization for Suppressing Charge Recombination

Liu, Xiaoyu; Yan, Yajie; Honarfar, Alireza LU ; Yao, Yao; Zheng, Kaibo LU and Liang, Ziqi (2019) In Advanced Science
Abstract


Nonfullerene acceptors (NFAs)-based organic solar cells (OSCs) have recently drawn considerable research interests; however, their excitonic dynamics seems quite different than that of fullerene acceptors-based devices and remains to be largely explored. A random terpolymer of PBBF11 to pair with a paradigm NFA of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) such that both complementary optical absorption and very small offsets of both highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels are acquired is designed and synthesized.... (More)


Nonfullerene acceptors (NFAs)-based organic solar cells (OSCs) have recently drawn considerable research interests; however, their excitonic dynamics seems quite different than that of fullerene acceptors-based devices and remains to be largely explored. A random terpolymer of PBBF11 to pair with a paradigm NFA of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) such that both complementary optical absorption and very small offsets of both highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels are acquired is designed and synthesized. Despite the small energy offsets, efficient electron/hole transfer between PBBF11 and ITIC is both clearly observed from steady-state photoluminescence and transient absorption spectra and also supported by the measured low exciton binding energy in ITIC. Consequently, the PBBF11:ITIC-based OSCs afford an encouraging power conversion efficiency (PCE) of 10.02%. Although the good miscibility of PBBF11 and ITIC induces a homogenous blend film morphology, it causes severe charge recombination. The fullerene acceptor of PC
71
BM with varying loading ratios is therefore added to modulate film morphology to effectively reduce the charge recombination. As a result, the optimal OSCs based on PBBF11:ITIC:PC
71
BM yield a better PCE of 11.4% without any additive or annealing treatment.

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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
charge recombination, film morphology, hole and electron transfer, nonfullerene acceptors, organic solar cells
in
Advanced Science
publisher
John Wiley & Sons
external identifiers
  • scopus:85061838597
ISSN
2198-3844
DOI
10.1002/advs.201802103
language
English
LU publication?
yes
id
6a683f8b-a035-456c-a88e-32f4246f56a8
date added to LUP
2019-03-04 12:45:52
date last changed
2019-03-27 04:39:41
@article{6a683f8b-a035-456c-a88e-32f4246f56a8,
  abstract     = {<p><br>
                                                         Nonfullerene acceptors (NFAs)-based organic solar cells (OSCs) have recently drawn considerable research interests; however, their excitonic dynamics seems quite different than that of fullerene acceptors-based devices and remains to be largely explored. A random terpolymer of PBBF11 to pair with a paradigm NFA of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) such that both complementary optical absorption and very small offsets of both highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels are acquired is designed and synthesized. Despite the small energy offsets, efficient electron/hole transfer between PBBF11 and ITIC is both clearly observed from steady-state photoluminescence and transient absorption spectra and also supported by the measured low exciton binding energy in ITIC. Consequently, the PBBF11:ITIC-based OSCs afford an encouraging power conversion efficiency (PCE) of 10.02%. Although the good miscibility of PBBF11 and ITIC induces a homogenous blend film morphology, it causes severe charge recombination. The fullerene acceptor of PC                             <br>
                            <sub>71</sub><br>
                                                         BM with varying loading ratios is therefore added to modulate film morphology to effectively reduce the charge recombination. As a result, the optimal OSCs based on PBBF11:ITIC:PC                             <br>
                            <sub>71</sub><br>
                                                         BM yield a better PCE of 11.4% without any additive or annealing treatment.                         <br>
                        </p>},
  articleno    = {1802103},
  author       = {Liu, Xiaoyu and Yan, Yajie and Honarfar, Alireza and Yao, Yao and Zheng, Kaibo and Liang, Ziqi},
  issn         = {2198-3844},
  keyword      = {charge recombination,film morphology,hole and electron transfer,nonfullerene acceptors,organic solar cells},
  language     = {eng},
  month        = {02},
  publisher    = {John Wiley & Sons},
  series       = {Advanced Science},
  title        = {Unveiling Excitonic Dynamics in High-Efficiency Nonfullerene Organic Solar Cells to Direct Morphological Optimization for Suppressing Charge Recombination},
  url          = {http://dx.doi.org/10.1002/advs.201802103},
  year         = {2019},
}