Preparation of Doped Graphene Quantum Dots with Bright and Excitation-Independent Blue Fluorescence

Abstract

Highly bright-fluorescent N (nitrogen), S (sulfur) co-doped graphene quantum dots (GQDs) were synthesized through an modified hydrothermal method. The doped GQDs are smaller than 10 nm in size in average and stable in aqueous solution. Unlike many reports on graphene oxide (GO), the as-synthesized doped GQDs exhibit bright blue photoluminescence (PL) emission and the emission wavelength is excitation-independent. The intriguling results indicate that GQDs may have great potential in the optic and optoelectronic applications.