The Role of the Side Chain on the Performance of N-type Conjugated Polymers in Aqueous Electrolytes
Maria, Iuliana P.
Donahue, Mary J.
Barth, Katrina J.
Makdah, Beatrice E.
Barnes, Piers R.F.
Reid, Obadiah G.
Malliaras, George G.
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Chemical Science Program
KAUST Solar Center (KSC)
Physical Science and Engineering (PSE) Division
Online Publication Date2018-04-24
Print Publication Date2018-05-08
Permanent link to this recordhttp://hdl.handle.net/10754/627699
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AbstractWe report a design strategy that allows the preparation of solution processable n-type materials from low boiling point solvents for organic electrochemical transistors (OECTs). The polymer backbone is based on NDI-T2 copolymers where a branched alkyl side chain is gradually exchanged for a linear ethylene glycol-based side chain. A series of random copolymers was prepared with glycol side chain percentages of 0, 10, 25, 50, 75, 90, and 100 with respect to the alkyl side chains. These were characterized to study the influence of the polar side chains on interaction with aqueous electrolytes, their electrochemical redox reactions, and performance in OECTs when operated in aqueous electrolytes. We observed that glycol side chain percentages of >50% are required to achieve volumetric charging, while lower glycol chain percentages show a mixed operation with high required voltages to allow for bulk charging of the organic semiconductor. A strong dependence of the electron mobility on the fraction of glycol chains was found for copolymers based on NDI-T2, with a significant drop as alkyl side chains are replaced by glycol side chains.
CitationGiovannitti A, Maria IP, Hanifi D, Donahue MJ, Bryant D, et al. (2018) The Role of the Side Chain on the Performance of N-type Conjugated Polymers in Aqueous Electrolytes. Chemistry of Materials. Available: http://dx.doi.org/10.1021/acs.chemmater.8b00321.
SponsorsWe thank Iain Hamilton for assistance in measuring contact angle data and Nathan Cheetham for recording solid state absorption spectra. We acknowledge funding from KAUST and BASF, as well as EPSRC Projects EP/P02484X/1, EP/G037515/1, EP/M005143/1, EP/N509486/1; EC FP7 Project SC2 (610115); and EC H2020 Project SOLEDLIGHT (643791) In addition, this project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 742708). O.G.R. and G.R. acknowledge support for the microwave conductivity and photoluminescence measurements from the Solar Photochemistry Program, Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy under Contract DE-AC36-08-GO28308 with the National Renewable Energy Laboratory. D.H. gratefully acknowledges support from NSF-GFRP.
PublisherAmerican Chemical Society (ACS)
JournalChemistry of Materials