The sample quality of graphene has been improved significantly since its discovery. One factor that limited further improvements has not been investigated directly so far, namely corrugations in the graphene sheet, i.e. microscopic distortions that form even when placed on atomically flat surfaces. Such corrugations can scatter the electrons when moving through an electronic device. Like bumps on a road that slow the pace of travel, corrugations in graphene slow traveling electrons. After flattening the corrugations, electrons move effectively faster through a graphene sheet.
Click here for original story, Flatter graphene, faster electrons: Technique flattens corrugations in graphene layers to improve samples
Source: Phys.org