▎ 摘　　要

We report an entirely organic-free method to suspend monolayer graphene grown by chemical vapour deposition over 10-20 mu m apertures in a Cu substrate. Auger electron spectroscopy, Raman spectroscopy, scanning electron microscope, and transmission electron microscope measurements confirm high quality graphene with no measurable contamination beyond that resulting from air exposure. This method can be used to prepare graphene for fundamental studies and applications where the utmost cleanliness and structural integrity are required. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4737415]