Fluorination of Edges and Central Areas of Monolayer Graphene by SF_6 and CHF_3 Plasma Treatments

摘要

In this work, we report the fluorination of edges and central areas of monolayer graphene by SF_6 and CHF_3 plasma treatments. After fluorination by SF_6 plasma, G and 2D peaks of Raman spectroscopy for the edges have upshifts, which are much bigger than the upshifts for central areas of monolayer graphene. For the intensity ratio of I(2D)/I(G), it becomes smaller after SF_6 plasma treatments and magnitude of change is similar for the edges and that of the central areas. These observations indicate that the fluorination by SF_6 plasma treatments can induce p-doping to graphene, which is more significant for the edges comparing to the central areas. Moreover, the ratio of I(D)/I(G) becomes larger both for the edges and the central areas. For CHF_3 plasma treatments, although similar results can be obtained, the p-doping to graphene is less and more defects are introduced comparing to SF_6 plasma treatment. Therefore, for fluorination of monolayer graphene, SF_6 plasma is better than CHF_3 plasma.