Effect of intermolecular interactions on charge and exciplex formation in high-performance organic semiconductors

摘要

We present optical, photoluminescent (PL), and photoconductive properties of functionalized anthradithiophene (ADT) derivatives and their composites. Solution-deposited ADT films exhibit charge carrier mobilities of over 1.5 cm~2/(Vs), high PL quantum yields, and high photoconductivity. We show that molecular arrangement and intermolecular interactions significantly contribute to (opto)electronic properties of guest-host thin films of these pi-stacked materials. Specifically, the formation of aggregates plays an important role in establishing efficient conduction pathways in ADT derivatives dispersed in a host matrix. In addition, the extent and nature of aggregation and the resulting changes in PL and photoconductive behavior can be effectively manipulated through different film fabrications techniques. Furthermore, energy transfer and exciplex formation has been shown to occur between two different ADT derivatives, which also alters the photoconductive response of the systems. We explore the dependence of the photoconductive response of such guest-host systems on excitation wavelength.