Designing light-harvesting antenna systems based on superradiant molecular aggregates

The efficiency of synthetic light-harvesting antenna systems for energy transfer and trapping that incorporate complex assemblies of chromophores can be significantly dictated by mixed states that arise through electronic couplings among aggregates of donor or acceptor chromophores. Such electronic interactions - that perturb donor emission spectra, radiative decay rate, and acceptor absorption spectra - cannot be accounted for by Förster theory. In the present report, use of collective superradiant donor and/or acceptor transitions to mediate rapid 'supertransfer' of excitation energy is considered. Design principles that can be used to incorporate complex molecular assemblies into light-harvesting devices are elucidated by calculations of energy supertransfer dynamics in model assemblies. It is concluded that design based only on donor emission and acceptor absorption spectra can be misguiding because of the importance of the precise arrangement of the molecular constituents that collectively give rise to those electronic transitions.