High Charge Mobility in Discotic Liquid-Crystalline Triindoles: Just a Core Business?

摘要

A key parameter in the performance of organic electronics devices is the mobility of charges. On the macroscopic level, it has been demonstrated that the highest charge carrier mobilities are obtained in highly ordered single-crystalline materials. However, the inherent fragility of single crystals poses serious technological problems, thus considerably limiting their practical applications. An interesting alternative is offered by discotic mesogens, which are typically composed of a central aromatic core substituted with flexible alkylic chains. Cores tend to form columnar stacks, maximizing π-orbital overlap between adjacent molecules and thus favoring a one-dimensional migration of charge carriers.Furthermore, the inherent fluidity of liquid crystals induces advantageous properties, such as the ability to self-heal structural defects and easier alignment and processing from the. isotropic phase. However, fluidity is also associated with intrastack dynamism of the functional units that reduces carrier mobility in the bulk.