Energy transfer in supramolecular materials for new applications in photonics and electronics

Abstract

Supramolecular materials use self-assembly of molecular components to form complex architectures that may otherwise be extremely difficult to prepare. One of the fundamental aspects of this approach is that relatively weak intermolecular forces are used to direct the assembly of the subcomponents. An important point is how to achieve strong electronic communication throughout the material in view of the ‘looseness’ of the molecular constituents, which interact only weakly. This is particularly important for applications in molecular electronics where exciton delocalization and charge transport generally limit the overall device performance. This review focuses on recent advances in supramolecular materials and architectures that are engineered to possess efficient energy transfer between the self-assembled component in view of new applications in photonics and electronics. Many biological functions are performed by molecules that self-assemble into large structures, and this concept is also used in supramolecular chemistry to design artificial single-molecule devices. Ken-Tsung Wong from National Taiwan University and Dario Bassani from the University of Bordeaux in France review efforts in supramolecular chemistry to achieve a strong electrical connection between different sections of such devices, even if they are only connected via weak chemical bonds. A strong energy transfer is important for electronic and photonic applications and can be achieved through the control of various intermolecular forces, such as hydrogen bonds. A further issue is the directionality of the energy transfer in a molecule. This poses a challenge for applications such as solar cells but can be mitigated though the use of appropriate molecular geometries such as tubes or nanowires. The scope and limitations of using supramolecular interactions to control and direct energy transfer processes in self-assembled materials are discussed with emphasis on recent developments in the field.