Mechanisms of residual polymer removal in solvent mixtures after the graphene transfer and effects on channel conductivity gate control

After graphene transfer, solvent mixtures were used to remove residual PMMA, which efficiency was estimated by AFM, Raman spectroscopy, and CVC. That post-treatment gives: stress relaxation (2D peak shift, compared to trichloroethylene), 2D/G intensity ratio 1.1 changes to 2.6, clean graphene regions exceed 100–150 nm size; threshold point shifts to zero but the conductivity and mobility reduce. Ethanolamine functionalizes both PMMA and graphene.