Benzo[1,2-b:4,5-b′]Dithiophene-6,7-Difluoroquinoxaline Small Molecule Donors with >8% BHJ Solar Cell Efficiency

Handle URI:
http://hdl.handle.net/10754/625685
Title:
Benzo[1,2-b:4,5-b′]Dithiophene-6,7-Difluoroquinoxaline Small Molecule Donors with >8% BHJ Solar Cell Efficiency
Authors:
Liang, Ru-Ze; Wang, Kai; Wolf, Jannic Sebastian; Babics, Maxime; Wucher, Philipp; Thehaiban, Mohammad K. Al; Beaujuge, Pierre
Abstract:
Solution-processable small molecule (SM) donors are promising alternatives to their polymer counterparts in bulk-heterojunction (BHJ) solar cells. While SM donors with favorable spectral absorption, self-assembly patterns, optimum thin-film morphologies, and high carrier mobilities in optimized donor–acceptor blends are required to further BHJ device efficiencies, material structure governs each one of those attributes. As a result, the rational design of SM donors with gradually improved BHJ solar cell efficiencies must concurrently address: (i) bandgap tuning and optimization of spectral absorption (inherent to the SM main chain) and (ii) pendant-group substitution promoting structural order and mediating morphological effects. In this paper, the rational pendant-group substitution in benzo[1,2-b:4,5-b′]dithiophene–6,7-difluoroquinoxaline SMs is shown to be an effective approach to narrowing the optical gap (Eopt) of the SM donors (SM1 and SM2), without altering their propensity to order and form favorable thin-film BHJ morphologies with PC71BM. Systematic device examinations show that power conversion efficiencies >8% and open-circuit voltages (VOC) nearing 1 V can be achieved with the narrow-gap SM donor analog (SM2, Eopt = 1.6 eV) and that charge transport in optimized BHJ solar cells proceeds with minimal, nearly trap-free recombination. Detailed device simulations, light intensity dependence, and transient photocurrent analyses emphasize how carrier recombination impacts BHJ device performance upon optimization of active layer thickness and morphology.
KAUST Department:
KAUST Solar Center (KSC); Physical Sciences and Engineering (PSE) Division
Citation:
Liang R-Z, Wang K, Wolf J, Babics M, Wucher P, et al. (2017) Benzo[1,2-b :4,5-b ′]Dithiophene-6,7-Difluoroquinoxaline Small Molecule Donors with >8% BHJ Solar Cell Efficiency. Advanced Energy Materials: 1602804. Available: http://dx.doi.org/10.1002/aenm.201602804.
Publisher:
Wiley-Blackwell
Journal:
Advanced Energy Materials
KAUST Grant Number:
CRG_R2_13_BEAU_KAUST_1
Issue Date:
14-Jul-2017
DOI:
10.1002/aenm.201602804
Type:
Article
ISSN:
1614-6832
Sponsors:
R.-Z.L. and K.W. 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 analyses.
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1002/aenm.201602804/abstract
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorLiang, Ru-Zeen
dc.contributor.authorWang, Kaien
dc.contributor.authorWolf, Jannic Sebastianen
dc.contributor.authorBabics, Maximeen
dc.contributor.authorWucher, Philippen
dc.contributor.authorThehaiban, Mohammad K. Alen
dc.contributor.authorBeaujuge, Pierreen
dc.date.accessioned2017-10-03T12:49:33Z-
dc.date.available2017-10-03T12:49:33Z-
dc.date.issued2017-07-14en
dc.identifier.citationLiang R-Z, Wang K, Wolf J, Babics M, Wucher P, et al. (2017) Benzo[1,2-b :4,5-b ′]Dithiophene-6,7-Difluoroquinoxaline Small Molecule Donors with >8% BHJ Solar Cell Efficiency. Advanced Energy Materials: 1602804. Available: http://dx.doi.org/10.1002/aenm.201602804.en
dc.identifier.issn1614-6832en
dc.identifier.doi10.1002/aenm.201602804en
dc.identifier.urihttp://hdl.handle.net/10754/625685-
dc.description.abstractSolution-processable small molecule (SM) donors are promising alternatives to their polymer counterparts in bulk-heterojunction (BHJ) solar cells. While SM donors with favorable spectral absorption, self-assembly patterns, optimum thin-film morphologies, and high carrier mobilities in optimized donor–acceptor blends are required to further BHJ device efficiencies, material structure governs each one of those attributes. As a result, the rational design of SM donors with gradually improved BHJ solar cell efficiencies must concurrently address: (i) bandgap tuning and optimization of spectral absorption (inherent to the SM main chain) and (ii) pendant-group substitution promoting structural order and mediating morphological effects. In this paper, the rational pendant-group substitution in benzo[1,2-b:4,5-b′]dithiophene–6,7-difluoroquinoxaline SMs is shown to be an effective approach to narrowing the optical gap (Eopt) of the SM donors (SM1 and SM2), without altering their propensity to order and form favorable thin-film BHJ morphologies with PC71BM. Systematic device examinations show that power conversion efficiencies >8% and open-circuit voltages (VOC) nearing 1 V can be achieved with the narrow-gap SM donor analog (SM2, Eopt = 1.6 eV) and that charge transport in optimized BHJ solar cells proceeds with minimal, nearly trap-free recombination. Detailed device simulations, light intensity dependence, and transient photocurrent analyses emphasize how carrier recombination impacts BHJ device performance upon optimization of active layer thickness and morphology.en
dc.description.sponsorshipR.-Z.L. and K.W. 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 analyses.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1002/aenm.201602804/abstracten
dc.subject6,7-difluoroquinoxalineen
dc.subjectbenzo[1,2-b:4,5-b′]dithiopheneen
dc.subjectfullereneen
dc.subjectorganic photovoltaicsen
dc.subjectsmall molecule solar cellsen
dc.titleBenzo[1,2-b:4,5-b′]Dithiophene-6,7-Difluoroquinoxaline Small Molecule Donors with >8% BHJ Solar Cell Efficiencyen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center (KSC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalAdvanced Energy Materialsen
kaust.authorLiang, Ru-Zeen
kaust.authorWang, Kaien
kaust.authorWolf, Jannic Sebastianen
kaust.authorBabics, Maximeen
kaust.authorWucher, Philippen
kaust.authorThehaiban, Mohammad K. Alen
kaust.authorBeaujuge, Pierreen
kaust.grant.numberCRG_R2_13_BEAU_KAUST_1en
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