Extended Data Fig. 1: Roughness of graphene oxide on mica and suspended graphene membranes on the holey substrate.
From: Uniform thin ice on ultraflat graphene for high-resolution cryo-EM
a, Typical atomic force microscopy (AFM) image of graphene oxide nanosheets on mica. b, AFM image showing the thin area of graphene oxide from the marked region in (a). The arrow reveals the wrinkle of graphene oxide. c, Height profile along the white line as marked in (a). The maximum height difference of graphene oxide nanosheets can reach ~20 nm. d, Typical scanning electron microscopy (SEM) image of rough suspended graphene on a TEM grid, which was transferred from the CVD graphene grown on the copper foil. The arrow reveals wrinkles of rough graphene. e, Typical AFM image of rough suspended graphene on a TEM grid. The arrows reveal the wrinkles on the suspended graphene surface. f, Height profiles along the white lines as marked in (e). The maximum height difference of rough suspended graphene can be up to 10~20 nm. Source data are provided as a Source Data file.
