Strongly exchange-coupled triplet pairs in an organic semiconductor

Leah R. Weiss, Sam L. Bayliss, Felix Kraffert, Karl J. Thorley, John E. Anthony, Robert Bittl, Richard H. Friend, Akshay Rao, Neil C. Greenham, Jan Behrends

Research output: Contribution to journalArticlepeer-review

161 Scopus citations


From biological complexes to devices based on organic semiconductors, spin interactions play a key role in the function of molecular systems. For instance, triplet-pair reactions impact operation of organic light-emitting diodes as well as photovoltaic devices. Conventional models for triplet pairs assume they interact only weakly. Here, using electron spin resonance, we observe long-lived, strongly interacting triplet pairs in an organic semiconductor, generated via singlet fission. Using coherent spin manipulation of these two-triplet states, we identify exchange-coupled (spin-2) quintet complexes coexisting with weakly coupled (spin-1) triplets. We measure strongly coupled pairs with a lifetime approaching 3 μs and a spin coherence time approaching 1 μs, at 10 K. Our results pave the way for the utilization of high-spin systems in organic semiconductors.

Original languageEnglish
Pages (from-to)176-181
Number of pages6
JournalNature Physics
Issue number2
StatePublished - Feb 1 2017

Bibliographical note

Publisher Copyright:
© 2017 Macmillan Publishers Limited.

ASJC Scopus subject areas

  • Physics and Astronomy (all)


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