Robust electrical current modulation in functionalized graphene channels

Abstract

Within the approach based on chemical modification of domain boundaries of polycrystalline graphene, a transistor channel is proposed for enhanced current modulation, Ion/Ioff ratio, in the 3 to 5 order of magnitude. We observed that two types of samples functionalized by N-methylpirrolidone (NMP) and weakly fluorinated graphene are able to demonstrate high current modulation. Experimentally, Ion/Ioff ~ 103 was found for NMP functionalized graphene and Ion/Ioff ~ 104–105 for weakly fluorinated graphene. Modeling of these two systems allows us to clarify the mechanism of carrier transport in the multi-barrier films of functionalized graphene films. It is shown that remarkable value for Ion/Ioff as about 106 can be observed for the films comprising graphene regions (graphene quantum dots, GQDs) with size of ~ 30–300 nm and ~ 75–100 nm fluorinated graphene barriers. Relatively high values of Ion/Ioff ~ 103–105 are also predicted for large graphene areas separated with thin (100 nm) barriers for the weakly fluorinated graphene samples. Our study paves a way towards controllable 2D transistors.