Tunable Etching of CVD Graphene for Transfer Printing of Nanoparticles Driven by Desorption of Contaminants with Low Temperature Annealing

Due to its exceptional mechanical properties, graphene can be an ideal support for nanotransfer printing. However, in its as-received state, it is incompatible with some processes for preparing 2D arrays of colloidal nanoparticles from reverse micelle templating. By treating CVD graphene with low temperature annealing, we have created a universal carrier to transfer such nanoparticles onto organic surfaces, taking advantage of the activation of the graphene surface via oxygen plasma etching. Desorption of hydrocarbon contaminant species by low temperature annealing is essential to ensure that exposure of the CVD graphene to the plasma oxidizes the film rather than etching it, as confirmed by Raman, Attenuated Total Reflectance- Fourier Transform Infrared (ATR-FTIR), and X-ray photoelectron spectroscopy measurements. Upon transfer printing to an organic surface, the nanoparticles are sandwiched between the reduced graphene oxide-like layer and the organic surface as shown by scanning near-field optical microscopy (SNOM), making them ideal as an interlayer in organic devices. The combination of exposure to plasma and annealing gives two vectors for controlling the oxygen doping profile in the activated graphene on Cu, and suggests new avenues for patterning nanostructures in devices with processing sensitive active layers.