Mixed self-assembled monolayer of molecules with dipolar and acceptor character—Influence on hysteresis and threshold voltage in organic thinfilm transistors

In this report, we investigate the impact of the molecular dipole moment and redox active head groups (C60) in pure and mixed self-assembled monolayers (SAMs), which serve as an ultra-thin hybrid dielectric layer in low-voltage operating organic thin-film transistors. We show that the dipole of the SAM-forming molecules affects the threshold voltage, while the concentration of redox-active C60 moieties determines the hysteresis in devices with α,α′-dihexyl-sexithiophene and pentacene as organic semiconductors