Scanning electron microscope at low voltage operation – a unique characterization tool for graphene layers

Graphene grown on Cu foils by chemical vapor deposition (CVD) technique has been investigated using commercially available scanning electron microscope at low voltage operation.The optimized conditions of SEM imaging carried out in a double-channel mode (registering secondary electrons type 1 (SE1) and backscattered electrons (BSE) images in a single scan) allowed for the visualization of typical features of graphene on Cu, such as folds, cracks and add-layers.The mechanism of thickness contrast observed in the BSE images was described in terms of low loss-BSE detection.Antioxidant qualities of graphene sheets on metallic substrate were confirmed by the ability of observation of the channeling contrast in Cu substrates at primary electrons energy of 0.5 keV.