Feasibility study of in-situ grown nanocrystalline graphene for humidity sensing

The application of in-situ transfer-free nanocrystalline graphene grown by polymer enhanced catalytic chemical vapor deposition [1] for sensing humidity in an atmospheric environment is investigated by electrical testing. Exposure of the graphene devices to humidity enriched air leads to a relative resistance change of an absolute value of up to 3.5%. Furthermore, post application of a hydrophobic hexamethyldisilazane self-assembled monolayer onto the graphene transistors is attempted leading to a shift of the charge neutrality point towards zero potential. Yet, our devices show more pronounced rayleigh scattering after the self-assembled monolayer application, decreasing the current by a factor of 3.