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

Abstract

Efficient energy transport over long distances is essential for optoelectronic and light-harvesting devices. Although self-assembled nanofibers of organic molecules have been shown to exhibit long exciton diffusion lengths, alignment of these nanofibers into films with large, organized domains with similar properties remains a challenge. Here, we show how the functionalization of C3 -symmetric carbonyl-bridged triarylamine trisamide (CBT) oligodimethylsiloxane (oDMS) sidechains with 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 towards fully covered surfaces of highly aligned nanofibers through functionalization with oDMS. This article is protected by copyright. All rights reserved.