Highly Ordered Supramolecular Materials of Phase‐Separated Block Molecules for Long‐Range Exciton Transport

• Published in: Advanced materials (Weinheim) 2023-06, Vol.35 (25), p.e2300891-n/a
• Main Authors: Son, Martin H. C., Berghuis, Anton M., Waal, Bas F. M., Wenzel, Felix A., Kreger, Klaus, Schmidt, Hans‐Werner, Rivas, Jaime Gómez, Vantomme, Ghislaine, Meijer, E. W.
• Format: Article
• Language: English
• Subjects: alignment; Carbonyls; Crystal defects; diffusion; Domains; Excitons; long‐range transport; Materials science; Nanofibers; Optoelectronic devices; Organic chemistry; Self-assembly
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202300891

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 C3‐symmetric carbonyl‐bridged triarylamine trisamide (CBT) with oligodimethylsiloxane (oDMS) side chains of discrete length leads to fully covered surfaces with aligned domains up to 125 × 70 µm2 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 oDMS matrix. The oDMS 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 cm2 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 oDMS. Materials with columns of cores based on carbonyl‐bridged triarylamine trisamides functionalized with oligodimethylsiloxane side chains of discrete length are synthesized and characterized. Within these columns, the well‐defined ordering allows for diffusion lengths of >100 nm and exciton diffusivity values of ≈0.05 cm2 s−1.