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High-performance polymer semiconducting heterostructure devices by nitrene-mediated photocrosslinking of alkyl side chains

Nature Materials volume 9, pages 152–158 (2010)Cite this article

Abstract

Heterostructures are central to the efficient manipulation of charge carriers, excitons and photons for high-performance semiconductor devices. Although these can be formed by stepwise evaporation of molecular semiconductors, they are a considerable challenge for polymers owing to re-dissolution of the underlying layers. Here we demonstrate a simple and versatile photocrosslinking methodology based on sterically hindered bis(fluorophenyl azide)s. The photocrosslinking efficiency is high and dominated by alkyl side-chain insertion reactions, which do not degrade semiconductor properties. We demonstrate two new back-infiltrated and contiguous interpenetrating donor–acceptor heterostructures for photovoltaic applications that inherently overcome internal recombination losses by ensuring path continuity to give high carrier-collection efficiency. This provides the appropriate morphology for high-efficiency polymer-based photovoltaics. We also demonstrate photopatternable polymer-based field-effect transistors and light-emitting diodes, and highly efficient separate-confinement-heterostructure light-emitting diodes. These results open the way to the general development of high-performance polymer semiconductor heterostructures that have not previously been thought possible.

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Figure 1: Characterization of the FPA methodology in polymer OSCs.
Figure 2: Directed heterostructures with lateral texture.
Figure 3: Polymer PVs.
Figure 4: High-performance photocrosslinked polymer FETs and LEDs.
Figure 5: High-efficiency separate-confinement-heterostructure LEDs. Device structure: glass/ITO/65-nm PEDT:PSSH–x-nmTFB/70-nm F8BT/3-nm Ca/Al.

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Acknowledgements

We thank N. Conway, I. Grizzi, J. Halls, R. Wilson and the CDT team, L.-Y. Wong, J.-M. Zhuo, L.-H. Zhao, B. Anto and the ONDL team for discussions and technical help. We thank C.-W. Tan and his workshop team for building the measurement rigs. The work in Singapore was supported by MOE ARF (Project 144-000-214-112) and A* STAR SERC (Project 052-117-0030).

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Author notes

  1. Rui-Qi Png and Perq-Jon Chia: These authors contributed equally to the work

Authors and Affiliations

  1. Department of Physics, National University of Singapore, Lower Kent Ridge Road, S117542, Singapore

    Rui-Qi Png, Perq-Jon Chia, Bo Liu, Sankaran Sivaramakrishnan, Mi Zhou, Lay-Lay Chua, Richard H. Friend & Peter K. H. Ho

  2. Department of Chemistry, National University of Singapore, Lower Kent Ridge Road, S117543, Singapore

    Jie-Cong Tang, Hardy S. O. Chan & Lay-Lay Chua

  3. Cavendish Laboratory, University of Cambridge, JJ Thomson Road, Cambridge, CB3 OHE, UK

    Siong-Hee Khong, Lay-Lay Chua & Richard H. Friend

  4. Cambridge Display Technology Ltd, Bldg 2020, Cambourne Business Park, Cambridgeshire, CB3 6DW, UK

    Jeremy H. Burroughes

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Contributions

R.Q.P. and P.J.C. planned and carried out most of the experimental work and data analyses, J.C.T. synthesized the materials, B.L., S.S., M.Z. and S.H.K. assisted with the experiments and data analyses, H.S.O.C. provided insights and J.H.B., L.L.C., R.H.F. and P.K.H.H. guided the work.

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Correspondence to Lay-Lay Chua, Richard H. Friend or Peter K. H. Ho.

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Png, RQ., Chia, PJ., Tang, JC. et al. High-performance polymer semiconducting heterostructure devices by nitrene-mediated photocrosslinking of alkyl side chains. Nature Mater 9, 152–158 (2010). https://doi.org/10.1038/nmat2594

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