The entangled triplet pair state in acene and heteroacene materials

Keong Yong, C. et al. (2017) The entangled triplet pair state in acene and heteroacene materials. Nature Communications, 8, 15953. (doi: 10.1038/ncomms15953) (PMID:28699637) (PMCID:PMC5510179)

Abstract

Entanglement of states is one of the most surprising and counter-intuitive consequences of quantum mechanics, with potent applications in cryptography and computing. In organic materials, one particularly significant manifestation is the spin-entangled triplet-pair state, which mediates the spin-conserving fission of one spin-0 singlet exciton into two spin-1 triplet excitons. Despite long theoretical and experimental exploration, the nature of the triplet-pair state and inter-triplet interactions have proved elusive. Here we use a range of organic semiconductors that undergo singlet exciton fission to reveal the photophysical properties of entangled triplet-pair states. We find that the triplet pair is bound with respect to free triplets with an energy that is largely material independent (∼30 meV). During its lifetime, the component triplets behave cooperatively as a singlet and emit light through a Herzberg–Teller-type mechanism, resulting in vibronically structured photoluminescence. In photovoltaic blends, charge transfer can occur from the bound triplet pairs with >100% photon-to-charge conversion efficiency.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Bayliss, Dr Sam
• Authors: Keong Yong, C., Musser, A. J., Bayliss, S. L., Lukman, S., Tamura, H., Bubnova, O., Hallani, R. K., Meneau, A., Resel, R., Maruyama, M., Hotta, S., Herz, L. M., Beljonne, D., Anthony, J. E., Clark, J., and Sirringhaus, H.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Nature Communications
• Publisher: Nature Research
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Nature Communications 8: 15953
• Publisher Policy: Reproduced under a Creative Commons License