Electronic doping of organic semiconductors is essential for their usage in highly efficient optoelectronic devices. Although molecular and metal complex-based dopants have already enabled significant progress of devices based on organic semiconductors, there remains a need for clean, efficient and low-cost dopants if a widespread transition towards larger-area organic electronic devices is to occur. Here we report dimethyl sulfoxide adducts as p-dopants that fulfil these conditions for a range of organic semiconductors. These adduct-based dopants are compatible with both solution and vapour-phase processing. We explore the doping mechanism and use the knowledge we gain to ‘decouple’ the dopants from the choice of counterion. We demonstrate that asymmetric p-doping is possible using solution processing routes, and demonstrate its use in metal halide perovskite solar cells, organic thin-film transistors and organic light-emitting diodes, which showcases the versatility of this doping approach.
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The datasets used in this work are available in the Oxford University Research Archive repository48.
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This research has mainly received funding from the European Commission (PERTPV- agreement no. 763977) and EPSRC (EP/M005143/1 and EP/S004947/1). M.R. has received funding from the EC FP 7 MSCA—Career Integration Grant (630864) and M.R. and S.V.K. acknowledge funding from the EPSRC WAFT project (EP/M015173/1). R.W. is supported by EPSRC CDT Plastic Electronics (EP/L016702/1). P.K.N. acknowledges support from the Department of Atomic Energy, Government of India, under Project Identification no. RTI 4007 and SERB India core research grant (CRG/2020/003877). F.Z., X.L. and A.K. acknowledge funding from National Science Foundation under grants DMR-1506097 and DMR-1807797. S.N. acknowledges Marie Skłodowska-Curie Actions individual fellowships (grant agreement no. 659306) and a start-up grant from CSIR-IMMT, India. T.M. and V.G. acknowledge funding from European Regional Development Fund (project no. 01.2.2-LMT-K-718-03-0040) under a grant agreement with the Research Council of Lithuania (LMTLT). T.D.A. and A.B. are grateful to King Abdullah University of Science and Technology (KAUST), KAUST Solar Centre and KAUST Office for Sponsored Research (OSR) for the financial support under award no: OSR-2019-CRG8-4095, no. OSR-2018-CARF/CCF-3079. J.L. and C.G. are grateful for support for the NanoSIMS facility from EPSRC under grant EP/M018237/1. We thank I. McPherson for his help in mass spectrometry measurements and M. Heeney for providing the C16IDT-BT polymer.
A patent based on this work has been filed (international application number PCT/GB2018/053014) by the University of Oxford. H.J.S. is a co-founder of Oxford PV Ltd and Helio Display Materials. The remaining authors declare no competing interests.
Peer review information Nature Materials thanks Adam Moule and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Sakai, N., Warren, R., Zhang, F. et al. Adduct-based p-doping of organic semiconductors. Nat. Mater. (2021). https://doi.org/10.1038/s41563-021-00980-x