Highly Ordered Supramolecular Materials of Phase‐Separated Block Molecules for Long‐Range Exciton Transport
Martin H. C. van Son, Anton Matthijs Berghuis, Bas F. M. de Waal, Felix A. Wenzel, Klaus Kreger, Hans‐Werner Schmidt, Jaime Gómez Rivas, Ghislaine Vantomme, E. W. Meijer
Abstract
Abstract Efficient energy transport over long distances is essential for optoelectronic and light‐harvesting devices. Although self‐assembled nanofibers of organic molecules are shown to exhibit long exciton diffusion lengths, alignment of these nanofibers into films with large, organized domains with similar properties remains a challenge. Here, it is shown how the functionalization of C 3 ‐symmetric carbonyl‐bridged triarylamine trisamide (CBT) with oligodimethylsiloxane ( o DMS) side chains of discrete length leads to fully covered surfaces with aligned domains up to 125 × 70 µm 2 in which long‐range exciton transport takes place. The nanoscale morphology within the domains consists of highly ordered nanofibers with discrete intercolumnar spacings within a soft amorphous o DMS matrix. The o DMS prevents bundling of the CBT fibers, reducing the number of defects within the CBT columns. As a result, the columns have a high degree of coherence, leading to exciton diffusion lengths of a few hundred nanometers with exciton diffusivities (≈0.05 cm 2 s −1 ) that are comparable to those of a crystalline tetracene. These findings represent the next step toward fully covered surfaces of highly aligned nanofibers through functionalization with o DMS.