Functionalization of graphene and few-layer graphene with aqueous solution of hydrofluoric acid

•Modification of graphene by a few-minute treatment in H2O:HF solution.•Strong increase in resistivity, change in Raman spectra, formation of corrugated film.•Material for electronic applications due to functionalization.•Formation of graphene quantum dots in an insulated matrix.•Local protection of the graphene against functionalization with HF.

In the present study, conditions suitable for efficient modification of graphene and few-layer graphene (FLG) films with aqueous solutions of hydrofluoric acid (HF) and for local protection of the graphene against such modification in isopropyl alcohol were identified. A combination of the two treatments gives one a key to nanodesign of graphene-based 2D devices. It was found that a few-minute treatment of graphene or FLG in HF aqueous solutions (∼1 min for graphene and ∼5 min for FLG films about 5 nm thick) leads to strong changes in the structural and electrical properties of graphene involving a step-like increase in resistivity (up to 1011 Ω/□). Two types of materials were obtained after different times of treatment: (i) promising for electronic applications of the material due to a combination of high carrier mobility, high conductivity, and strong current modulation by gate voltage (up to four orders of magnitude); (ii) a material with insulating properties and graphene quantum dots embedded in an insulating matrix.