Self-organization of supramolecular helical dendrimers into complex electronic materials

TLDR: This work finds that attaching conducting organic donor or acceptor groups to the apex of the dendrons leads to supramolecular nanometre-scale columns that contain in their cores π-stacks of donors, acceptors or donor–acceptor complexes exhibiting high charge carrier mobilities.

Abstract: The discovery of electrically conducting organic crystals1 and polymers1,2,3,4 has widened the range of potential optoelectronic materials5,6,7,8,9, provided these exhibit sufficiently high charge carrier mobilities6,7,8,9,10 and are easy to make and process. Organic single crystals have high charge carrier mobilities but are usually impractical11, whereas polymers have good processability but low mobilities1,12. Liquid crystals exhibit mobilities approaching those of single crystals and are suitable for applications13,14,15,16,17,18, but demanding fabrication and processing methods limit their use. Here we show that the self-assembly of fluorinated tapered dendrons can drive the formation of supramolecular liquid crystals with promising optoelectronic properties from a wide range of organic materials. We find that attaching conducting organic donor or acceptor groups to the apex of the dendrons leads to supramolecular nanometre-scale columns that contain in their cores π-stacks of donors, acceptors or donor–acceptor complexes exhibiting high charge carrier mobilities. When we use functionalized dendrons and amorphous polymers carrying compatible side groups, these co-assemble so that the polymer is incorporated in the centre of the columns through donor–acceptor interactions and exhibits enhanced charge carrier mobilities. We anticipate that this simple and versatile strategy for producing conductive π-stacks of aromatic groups, surrounded by helical dendrons, will lead to a new class of supramolecular materials suitable for electronic and optoelectronic applications.