Fate of Photoexcited Molecular Antennae - Intermolecular Energy Transfer versus Photodegradation Assessed by Quantum Dynamics

Abstract

The present computational study aims to unravel the competitive photoinduced intermolecular energy transfer and electron transfer phenomena in a light-harvesting antenna with potential applications in dye-sensitized solar cells and photocatalysis. A series of three thiazole dyes with hierarchically overlapping emission and absorption spectra, embedded in a methacrylate-based polymer backbone, is employed to absorb light over the entire visible region. Intermolecular energy transfer in such antenna proceeds via energy transfer from dye-to-dye and eventually to a photosensitizer. Initially, the ground and excited state properties of the three push–pull-chromophores (e.g., with respect to their absorption and emission spectra as well as their equilibrium structures) are thoroughly evaluated using state-of-the-art multiconfigurational methods and computationally less demanding DFT and TDDFT simulations. Subsequently, the potential energy landscape for the three dyads, formed by the π-stacked dyes as occurring...