The transfer of chemical vapor deposited (CVD) monolayer graphene by using poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole-co-tetrafluoroethylene] (Teflon AF1600) fluoropolymer (FP) as a sacrificial nanolayer is demonstrated. Owing to the chemical inertness of FPs, the AF1600-assisted transfer produces an ultraclean surface with excellent transfer integrity. Compared with the widely used poly(methyl methacrylate)-assisted transfer, AF1600-assisted transfer produces better overall transfer quality as measured by root-mean-square (RMS) roughness. Adding a noncovalent surface monolayer between the graphene and the FP facilitates the FP removal after graphene transfer, resulting in a surface with RMS roughness of 0.4-0.5 nm due to a better reduction of the surface residue after transfer. The remaining residue is found to be primarily associated with thermal-expansion ripples in the graphene that act as trapping sites for the low-molecular-weight FP particles. This work provides a scalable solution to clean CVD graphene transfer for many applications, particularly in sensors where surface cleanliness is paramount. The use of prefunctionalized graphene via self-assembled monolayers as molecular scale passivation layer could further enhance its utility as an integration scheme for graphene sensors.
Bibliographical noteFunding Information:
The authors acknowledge funding from Boston Scientific Corporation. Parts of this work were performed in the Characterization Facility, University of Minnesota, which receives partial support from the National Science Foundation (NSF) through the MRSEC (Award DMR-2011401) program. Portions of this work were also performed in the Minnesota Nano Center, which is supported by the NSF through the National Nanotechnology Coordinated Infrastructure (NNCI) under Award ECCS-2025124.
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- CVD graphene
- noncovalent functionalization