Reversibility of defect formation during oxygen‐assisted electron‐beam‐induced etching of graphene.

Abstract: We explore the defect formation on single‐layer graphene partially suspended over a microcavity upon etching by a focused electron beam in a reactive oxygen atmosphere. The formation of oxygenated defects in an area of several μm² around the cut is studied by Raman spectroscopy. The narrow symmetric Raman D band has the same bandwidth as the G band line width of supported graphene. For suspended graphene, the D bandwidth is larger. From the ratio of the intensity of the Raman D and D′ band (I_D/I_D′), it is concluded that mainly sp³‐type defects are formed on supported graphene and more defects with a different spectral signature are formed on suspended graphene. Annealing in reductive H₂/Ar atmosphere is found to remove bonded oxygen on supported graphene, whereas on suspended graphene with higher density of defects, defects are removed only partially. [ABSTRACT FROM AUTHOR]