Electrical properties of graphene field-effect transistors functionalized with aryldiazonium salts

Functionalization of graphene field-effect transistors (G-FETs) is necessary to ensure specificity in sensor applications. Among functionalization strategies, aryldiazonium salts are often chosen to form stable covalent adducts. Here we analyze the effect of this chemistry on the electrical properties of graphene field-effect transistors. First, we conducted an extensive review of published experiments and developed a theoretical framework to compare data obtained indifferent conditions (channel size, reagent concentration, incubation time). From the aggregated dataset, we found that the electronegativity of the para group seems to have little impact on the electrical response, which contrasts with conclusions found in the literature. We also found that the type of graphene (exfoliated, CVD, RGO) seems to have a much more dominant impact, which could explain strong differences between previous studies. Finally, we argue that device-to-device variations are significant, and we propose an experimental design based on multiple GFETs arrays and statistical analysis to unambiguously characterize the effect of aryldiazonium functionalization on graphene transport properties.