Origin of tunable photoluminescence from graphene quantum dots synthesized via pulsed laser ablation
- Resource Type
- Authors
- Hsiu-Ying Huang; Chi-Tsu Yuan; T. N. Lin; C. A. J. Lin; Ji-Lin Shen; Svette Reina Merden Santiago
- Source
- Physical chemistry chemical physics : PCCP. 18(32)
- Subject
- Materials science
Tunable photoluminescence
business.industry
Graphene
General Physics and Astronomy
02 engineering and technology
010402 general chemistry
021001 nanoscience & nanotechnology
Multiwalled carbon
01 natural sciences
Green emission
0104 chemical sciences
Pulsed laser ablation
law.invention
Delocalized electron
Quantum dot
law
Optoelectronics
Physical and Theoretical Chemistry
0210 nano-technology
business
Excitation
- Language
- ISSN
- 1463-9084
A one-step synthesis of graphene quantum dots (GQDs) has been implemented using pulsed laser ablation (PLA) with carboxyl-functionalized multiwalled carbon nanotubes (MWCNTs). The synthesized GQDs with an average size smaller than 3 nm were obtained by the fragmentation of MWCNTs via oxidative cutting. The GQDs can generate tunable photoluminescence (PL) ranging from green to blue by controlling the PLA time. The PL spectrum (decay time) of the green GQDs remains unchanged under different excitation energies (emission energies), while that of the blue GQDs correlates with the excitation energy (emission energy). On the basis of the pH and temperature dependence of PL, we suggest that the localized intrinsic states associated with the sp(2) nanodomains and delocalized extrinsic states embedded on the GQD surface are responsible for blue and green emission in GQDs, respectively.