Application to free-standing monolayer graphene. (a) 40-nm nitride membrane with penetrating holes, covered by monolayer graphene. (b) Zoom in SEM image in (a) clearly shows free-standing graphene. (c) Sample preparation by microcapsule approach. (d) The plan-view TEM speimen is mounted on Cu grid and well-prepared. The free-standing graphene lies in the window for TEM observation. (e) Zoom in SEM image in (d) shows the back side of free-standing graphene. The structure remains undisturbed after sample preparation if comparing with (b). (f) Selected-area electron diffraction pattern of free-standing graphene.
Lan-Hsuan Lee 