Quaternary Organic Solar Cells Enhanced by Cocrystalline Squaraines with Power Conversion Efficiencies >10%
Abstract
The incorporation of multiple donors into the bulk-heterojunction layer of organic polymer solar cells (PSCs) has been demonstrated as a practical and elegant strategy to improve photovoltaics performance. However, it is challenging to successfully design and blend multiple donors, while minimizing unfavorable interactions (e.g., morphological traps, recombination centers, etc.). Here, a new Förster resonance energy transfer-based design is shown utilizing the synergistic nature of three light active donors (two small molecules and a high-performance donor–acceptor polymer) with a fullerene acceptor to create highly efficient quaternary PSCs with power conversion efficiencies (PCEs) of up to 10.7%. Within this quaternary architecture, it is revealed that the addition of small molecules in low concentrations broadens the absorption bandwidth, induces cocrystalline molecular conformations, and promotes rapid (picosecond) energy transfer processes. These results provide guidance for the design of multiple-donor systems using simple processing techniques to realize single-junction PSC designs with unprecedented PCEs.
Additional Information
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Received: March 28, 2016; Revised: June 13, 2016; Published online: August 11, 2016. T.G. and J.-S.H. contributed equally to this work. The authors gratefully acknowledge the National Science Foundation (DMR-1410171), NSF-CAREER award (CBET-0954985), the Yale Climate and Energy Institute (YCEI), and the NASA (CT Space Grant Consortium) for partial support of this work. B.G.B. also acknowledges support from the Edward A. Bouchet-Robertson Fellowship. This research was carried out in part at the Center for Functional Nanomaterials (CFN), and the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), which is supported by the U.S. Department of Energy (DoE), Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886. The SEM and AFM used were supported by YINQE and NSF MRSEC DMR 1119826 (CRISP). The authors further thank Michelle Vaisman from Yale Electrical Engineering Department for assistance with EQE and steady state PL measurements, as well as Dr. Jaemin Kong for useful discussions. A.D.T and J.-S.H. initially conceptualized the project. J.-S.H. performed the preliminary device experiments and T.G. designed and performed the rest of experiments necessary for publication, while B.G.B. assisted in film preparation. J.-S.H., T.G., and M.Y.S. performed the ultrafast experiments and resulting data analysis. J.-S.H. and T.G. performed the AFM and EQE experiments. C.-Y.N. and T.G. examined device performance in BNL. T.G., F.A., and K.G.Y. conducted GIXS experiments. T.G. and X.T. ran XPS studies. J.-S.H. and T.G. recorded the TEM images and F.A. performed cross-section SEM. L.M.G., P.R.M., and N.H. contributed to the synthesis of the squaraine dyes, PT8 polymer, and guided in data analysis. The authors declare no competing financial interests.Attached Files
Supplemental Material - aenm201600660-sup-0001-S1.pdf
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Additional details
- Eprint ID
- 72671
- Resolver ID
- CaltechAUTHORS:20161208-143152838
- DMR-1410171
- NSF
- CBET-0954985
- NSF
- Yale Climate and Energy Institute (YCEI)
- Connecticut Space Grant Consortium
- Edward A. Bouchet-Robertson Fellowship
- DE-AC02-98CH10886
- Department of Energy (DOE)
- Yale Institute for Nanoscience and Quantum Engineering (YINQE)
- DMR-1119826
- NSF
- Created
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2016-12-08Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field