Strongly exchange-coupled triplet pairs in an organic semiconductor


Type
Article
Change log
Authors
Weiss, LR 
Bayliss, SL 
Kraffert, F 
Thorley, KJ 
Anthony, JE 
Abstract

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 co-existing 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.

Description
Keywords
5108 Quantum Physics, 51 Physical Sciences
Journal Title
Nature Physics
Conference Name
Journal ISSN
1745-2473
1745-2481
Volume Title
Publisher
Springer Science and Business Media LLC
Sponsorship
Engineering and Physical Sciences Research Council (EP/M005143/1)
Engineering and Physical Sciences Research Council (EP/M006360/1)
Engineering and Physical Sciences Research Council (EP/G060738/1)
Gates-Cambridge Trust, Winton Programme for the Physics of Sustainability, Freie Universität Berlin within the Excellence Initiative of the German Research Foundation, Engineering and Physical Sciences Research Council (Grant ID: EP/G060738/1)
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