Fluctuating exchange interactions enable quintet multiexciton formation in singlet fission

Miles I Collins; Dane R McCamey; Murad J Y Tayebjee

doi:10.1063/1.5115816

Fluctuating exchange interactions enable quintet multiexciton formation in singlet fission

J Chem Phys. 2019 Oct 28;151(16):164104. doi: 10.1063/1.5115816.

Authors

Miles I Collins¹, Dane R McCamey¹, Murad J Y Tayebjee²

Affiliations

¹ ARC Centre of Excellence in Exciton Science, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia.
² School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia.

PMID: 31675884
DOI: 10.1063/1.5115816

Abstract

Several recent electron spin resonance studies have observed a quintet multiexciton state during the singlet fission process. Here, we provide a general theoretical explanation for the generation of this state by invoking a time-varying exchange coupling between pairs of triplet excitons and subsequently solving the relevant time-varying spin Hamiltonian for different rates at which the exchange coupling varies. We simulate experimental ESR spectra and draw qualitative conclusions about the adiabatic and diabatic transitions between triplet pair spin states.