Tuning the photoluminescence of graphene oxide quantum dots by photochemical fluorination

Tailoring the band gap and understanding the underlying mechanism are important for extending the applications of graphene quantum dots in optoelectronics. In this work, we synthesize fluorinated graphene oxide quantum dots (F-GOQDs) through a photochemical method, and study their optical properties. The obtained F-GOQDs exhibit a maximal blue-shift of photoluminescence (PL) emission of ca. 77 nm compared to that of the graphene oxide quantum dots (GOQDs). The PL shift results from the substitution of the hydroxyls and carbonyls groups with fluorine during the fluorination process, which can tune the band gap of the GOQDs. Density functional theory (DFT) calculations support our proposed mechanism for band gap tuning in the GOQDs through the use of fluorination. [Display omitted]