Optically Responsive Field-Effect Transistors Based on Graphene/Diarylethene Hybrid Films

Photochromic molecules are emerging as key components in advanced optoelectronic systems owing to their ability to undergo reversible light-induced structural transformations that modulate their optical and electronic properties. Here, we investigate the optical response and photoswitching behavior of two prototypical dioctadecyl-substituted diarylethenes (DTEs) in solution and as ultrathin films physisorbed onto graphene crystals. Photoswitching efficiency was quantified spectrophotometrically in both environments, revealing efficient and reversible interconversion between the open and closed isomeric forms. When assembled into physisorbed monolayers on graphene, these photoresponsive molecules provide a remote means of tuning the electronic properties of the hybrid interface. The morphology, optical characteristics, and electronic structure of DTE/graphene assemblies were systematically characterized and correlated with variations in drain current measured in field-effect transistors (FETs) incorporating the hybrid films as active channel components.