| 초록 |
Heteroatom doping of graphene quantum dots (GQDs) is an effective route to tune their electronic and optical properties. In this study, we report a simple and one-step method for the preparation of N-doped graphene quantum dots (N-GQDs) with excellent optical properties through the pulsed laser ablation in liquid (PLAL) process. The prepared N-GQDs exhibited superior optical properties and high quantum yield compared to pristine graphene quantum dots (0.8 % → 9.1%) due to the incorporation of N atoms into the carbon structures. A possible recombination mechanism of N-GQDs was investigated by time-resolved photoluminescence spectroscopy for a deep understanding of the increasing optical properties. The increase of N atoms incorporated in the GQDs resulted in an increased fraction of the short recombination lifetime from the intrinsic state. We also report a possible mechanism for the formation of the N atoms in the GQDs structure during PLAL process, which is explained based on the plasma plume, and nitrogen precursor decomposition model. |
