Energy Transport in Supramolecular (Super-)Structures with Tailored Excited-State Energy Landscapes

Place: Conference room (IMDEA Nanociencia)

Abstract:

Organic (nano-)photonics and molecular electronics applications require efficient charge and/or energy transport through assemblies of functional molecules. A key factor for transport was demonstrated to be high electronic and structural order, which, however, is very difficult to achieve by simple casting techniques. I will discuss how self-assembly into defined nanostructures can be used to create systems with tailored energy transport characteristics by controlling excited-state properties. Specifically, I will show robust self-assembly of a low-molecular-weight molecule (carbonyl-bridged triarylamine) into well-defined hierarchical supramolecular nanostructures. We resolve long-range and efficient energy transport within single nanostructures in real time. In combination with numerical
modelling, we extract their excited-state energy landscapes and how those impact on transport. In a second example, we exploit supramolecular superstructures, socalled Shish-Kebab-type structures, to investigate defined and highly aligned nanofibres based on the prototypical conjugated polymer poly(3-hexylthiophene), P3HT. Using hyperspectral imaging, we find that the excited-state energy landscape continuously changes as a function of position along nanofibres. In particular, a well-defined energy gradient is present, that might help in designing systems for directed transport of energy within organic nanostructures.