Polymer Main-Chain Substitution Effects on the Efficiency of Nonfullerene BHJ Solar Cells
Type
ArticleAuthors
Firdaus, Yuliar
Maffei, Luna Pratali
Cruciani, Federico

Müller, Michael A.
Liu, Shengjian
Lopatin, Sergei

Wehbe, Nimer
Ngongang Ndjawa, Guy Olivier

Amassian, Aram

Laquai, Frédéric

Beaujuge, Pierre

KAUST Department
Chemical Science ProgramElectron Microscopy
Imaging and Characterization Core Lab
KAUST Solar Center (KSC)
Material Science and Engineering Program
Organic Electronics and Photovoltaics Group
Physical Science and Engineering (PSE) Division
Surface Science
Date
2017-07-21Online Publication Date
2017-07-21Print Publication Date
2017-11Permanent link to this record
http://hdl.handle.net/10754/625699
Metadata
Show full item recordAbstract
“Nonfullerene” acceptors are proving effective in bulk heterojunction (BHJ) solar cells when paired with selected polymer donors. However, the principles that guide the selection of adequate polymer donors for high-efficiency BHJ solar cells with nonfullerene acceptors remain a matter of some debate and, while polymer main-chain substitutions may have a direct influence on the donor–acceptor interplay, those effects should be examined and correlated with BHJ device performance patterns. This report examines a set of wide-bandgap polymer donor analogues composed of benzo[1,2-b:4,5-b′]dithiophene (BDT), and thienyl ([2H]T) or 3,4-difluorothiophene ([2F]T) motifs, and their BHJ device performance pattern with the nonfullerene acceptor “ITIC”. Studies show that the fluorine- and ring-substituted derivative PBDT(T)[2F]T largely outperforms its other two polymer donor counterparts, reaching power conversion efficiencies as high as 9.8%. Combining several characterization techniques, the gradual device performance improvements observed on swapping PBDT[2H]T for PBDT[2F]T, and then for PBDT(T)[2F]T, are found to result from (i) notably improved charge generation and collection efficiencies (estimated as ≈60%, 80%, and 90%, respectively), and (ii) reduced geminate recombination (being suppressed from ≈30%, 25% to 10%) and bimolecular recombination (inferred from recombination rate constant comparisons). These examinations will have broader implications for further studies on the optimization of BHJ solar cell efficiencies with polymer donors and a wider range of nonfullerene acceptors.Citation
Firdaus Y, Maffei LP, Cruciani F, Müller MA, Liu S, et al. (2017) Polymer Main-Chain Substitution Effects on the Efficiency of Nonfullerene BHJ Solar Cells. Advanced Energy Materials 7: 1700834. Available: http://dx.doi.org/10.1002/aenm.201700834.Sponsors
Y.F. and L.P.M. contributed equally to this work. This publication is based upon work supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. CRG_R2_13_BEAU_KAUST_1. The authors acknowledge concurrent support under Baseline Research Funding from KAUST. The authors thank KAUST ACL for technical support in the mass spectrometry, GPC, and elemental analyses. The authors thank Z. Kan and M. Babics for the discussions in device characterizations.Publisher
WileyJournal
Advanced Energy MaterialsAdditional Links
http://onlinelibrary.wiley.com/doi/10.1002/aenm.201700834/fullae974a485f413a2113503eed53cd6c53
10.1002/aenm.201700834