Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. An ideal material for photon harvesting must allow control of the exciton diffusion length and directionality.
This is necessary in order to guide excitons to a reaction center, where their energy can drive a desired process. To reach this goal both of the following are required; short- and long-range structural order in the material and a detailed understanding of the excitonic transport. Here we present a strategy to realize crystalline chromophore assemblies with bespoke architecture.
We demonstrate this approach by assembling anthracene dibenzoic acid chromophore into a highly anisotropic, crystalline structure using a layer-by-layer process. We observe two different types of photoexcited states; one monomer-related, the other excimer-related. By incorporating energy-accepting chromophores in this crystalline assembly at different positions, we demonstrate the highly anisotropic motion of the excimer-related state along the [] direction of the chromophore assembly. In contrast, this anisotropic effect is inefficient for the monomer-related excited state.
The elemental steps in artificial photosynthetic systems are: photon absorption, funneling of the absorbed energy to a reaction center, and utilization of the energy at the reaction center to drive a desired reaction.
Nevertheless, optimizing the transfer of energy within chromophore assemblies to the reaction center is equally important. The transport or diffusion of the exciton the excited-state carrying the energy added to the molecule by the absorption of a photon between chromophores depends on the architecture of the assembled chromophores 2 , 3 , 4 , 5. Numerous studies have demonstrated that exciton motion in self-assembled organic molecular systems, conjugated polymers, nanostructures and organicβinorganic hybrid structures, critically depends on mesoscale order 6 , 7 , 8.
