Screening database to discover donor-acceptor copolymers for intramolecular singlet fission
Singlet fission is a multiple exciton generation process where a singlet exciton splits into two triplet excitons in adjacent chromophore centers, resulting in generation of two electron-hole pair carriers from each absorbed photon. Molecular systems displaying this phenomenon are very desired because they can, for instance, increase the efficiency of solar cells which must possesses both favorable energetics and appropriate electronic coupling. In this context, intramolecular bi-chromophores are particularly interesting in terms of their singlet fission capabilities. Specifically, these donor-acceptor copolymers have both proper electronic structure characteristics and modular molecular architecture. Nonetheless, no rational design principles exist for designing these systems, with the current state-of-the-art being based, primarily, on trial-and-error strategies. Thus, the field is ripe for the insight that can be brought by theoretical work, which has the potential to discover, in silico, new efficient singlet fission compounds.

The objective of the D3AiSF project is to combine state-of-the art computational tools with fundamental concepts of quantum chemistry in order to advance the intramolecular singlet fission field through high-throughput screening of efficient donor-acceptor copolymers and quantum dynamics simulations. The project’s first step involves designing an automated workflow capably of screening large numbers of singlet-fission capable donor-acceptor copolymers based on energy and coupling descriptors. Afterwards, a second stage focuses on the singlet-fission performance of the very best potential candidates, which are evaluated in terms of real time quantum dynamics of the nonadiabatic process, which will ultimately validate their relevance. Overall, this project stimulates both data-based theoretical chemistry and the field of intramolecular singlet fission through the computational design and discovery of novel materials.