▎ 摘 要
Graphene transistors with a dual-gate structure have been fabricated to study the effects of a functional dielectric substrate. From graphene's conductance modulation by using dual-gate voltage control in which a polymethyl methacrylate (PMMA) layer is employed as a top-gate dielectric, we propose that the interaction between the graphene and the functional material working as a back-gate dielectric substrate can be understood. We evaluated two graphene devices, one having the standard structure of Si/SiO2/graphene/PMMA/top-gate and the other employing periodically poled lithium niobate (PPLN) with the structure of PPLN/graphene/PMMA/top-gate. The feasibility of this approach is discussed in terms of the effect of the alternating polarization domains on graphene's charge transport.