Robust Processing of Small-Molecule:Fullerene Organic Solar Cells via Use of Nucleating Agents
[3];
[4];
[4];
[5]
- Department of Materials and Center for Plastic Electronics, Imperial College London, London SW7 2AZ, United Kingdom
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States; Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Materials Department and Materials Research Laboratory, University of California—Santa Barbara, Santa Barbara, California 93117, United States
- Department of Materials and Center for Plastic Electronics, Imperial College London, London SW7 2AZ, United Kingdom; School of Materials Science &, Engineering and School of Chemical &, Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
The power conversion efficiency (PCE) of small-molecule bulk heterojunction solar cells is highly sensitive to the 'ink' formulation used to produce the photoactive layer. Here we demonstrate that the addition of nucleating agents renders device fabrication notably less susceptible to the ink composition, promising a route toward more robust processing of efficient devices over large areas and enabling more facile materials screening. We selected as a model system blends of 7,7-[4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b]dithiophene-2,6-diyl]bis[6-fluoro-4-(5-hexyl-[2,2-bithiophen]-5-yl)benzo[c][1,2,5]thiadiazole](p-DTS(FBTTh2)2) as the donor and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) as the acceptor because this is one of the small-molecule OPV blends with a device performance that is most sensitive to ink formulation, especially when used with the processing aid diiodooctane (DIO). Addition of DIO is essential to obtain high device performances; however, a notable increase in device performance is only achieved over a very narrow DIO content regime. Use of nucleating agents drastically changes this situation and leads to well-performing devices even at extreme levels of DIO. We thus start to address here one of the great challenges in organic solar cell research: the fact that, too often, only a very limited composition range leads to high efficiency devices. This means that for every new donor or acceptor a multitude of formulations have to be tested, including in combination with processing aids, to ensure that promising materials are not overlooked. The use of nucleating agents, thus, promises to render materials discovery more straightforward as this dependency of device performance with composition can be reduced.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1478731
- Report Number(s):
- NREL/JA-5900-71214
- Journal Information:
- ACS Applied Energy Materials, Vol. 1, Issue 5; ISSN 2574-0962
- Publisher:
- American Chemical Society (ACS)
- Country of Publication:
- United States
- Language:
- English
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