Title: Effect of adamantane substitutions to improve properties of organic optoelectronic materials

Abstract

Nowadays many organic semiconductors have been developed to improve the device performance, where most of the efforts focus on the design and synthesis of new π-conjugated backbones. Alkyl chains (linear, branched) or fluoroalkyl chains are commonly used side chains in organic semiconductors. These side chains generally do not directly contribute to charge transport in organic semiconductors and are usually used as solubilizing groups. Adamantane is the simplest diamondoid and possesses exceptional physical properties. Moreover, adamantane is more stable saturated hydrocarbon isomer of such a small molecular weight. Here we present a new approach by adamantane substitution of π-conjugated dyes which have significant influence to final optical and electrical properties of studied materials. This allows us to systematically study the effect of adamantane solubilization side groups to induce π−π interactions between the conjugated cores through adamantyl–adamantyl stacking. Careful choice of adamantane substituent may provide a highly ordered crystalline organization of the material with the efficient interconnection of crystalline domains and intermolecular π-orbital overlap, thus providing charge carrier mobilities even higher than that of the parent material. This approach can be universally applied for many types of semiconducting organic materials containing the imide motive, where solubilization is achieved by side-group substitution.