Fig. 1: High-intactness and clean transfer method for single-layer suspended graphene with cyclododecane (CD) as support layer.

a Schematic illustration of the procedure for transferring graphene onto transmission electron microscopy (TEM) holey substrate. b The optical image of the as-transferred graphene on TEM grid with the assistance of CD. The light transparent substance is CD. c Scanning electron microscopy (SEM) image for single-layer suspended graphene on SiN holey substrate, the diameter for each hole is 10 µm. d Suspended graphene on TEM carbon substrate with uniform hole distribution, the diameter for each hole is 1.2 µm and the intactness is about 99%. e Suspended graphene on TEM lacey carbon substrate with holes in roughly 8 µm average diameter, and the calculated intactness is about 99%. f The suspended diameter for the single-layer suspended graphene is about 36 µm. g Intactness at different suspended diameters for single-layer suspended graphene obtained in this work. The error bar is obtained by the statistical results in Supplementary Figs 4–8.