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.