Tuning Enhancement Efficiency of Multiple Emissive Centers in Graphene Quantum Dots by Core-Shell Plasmonic Nanoparticles
Author(s)
Wang, Shujun
Clapper, Ashleigh
Chen, Peng
Wang, Lianzhou
Aharonoyich, Igor
Jin, Dayong
Li, Qin
Griffith University Author(s)
Year published
2017
Metadata
Show full item recordAbstract
Graphene quantum dots (GQDs) are emerging luminescent nanomaterials for energy, bioimaging, and optoelectronic applications. However, unlike conventional fluorophores, GQDs contain multiple emissive centers that result in a complex interaction with external electromagnetic fields. Here we utilize core–shell plasmonic nanoparticles to simultaneously enhance and modulate the photoluminescence (PL) intensities and spectral profiles of GQDs. By analyzing the spectral profiles, we show that the emissive centers are highly influenced by the proximity to the metal particles. Under optimal spacer thickness of 25 nm, the overall PL ...
View more >Graphene quantum dots (GQDs) are emerging luminescent nanomaterials for energy, bioimaging, and optoelectronic applications. However, unlike conventional fluorophores, GQDs contain multiple emissive centers that result in a complex interaction with external electromagnetic fields. Here we utilize core–shell plasmonic nanoparticles to simultaneously enhance and modulate the photoluminescence (PL) intensities and spectral profiles of GQDs. By analyzing the spectral profiles, we show that the emissive centers are highly influenced by the proximity to the metal particles. Under optimal spacer thickness of 25 nm, the overall PL displays a four-fold enhancement compared with a pristine GQD. However, detailed lifetime measurements indicate the presence of midgap states that act as the bottleneck for further enhancement. Our results offer new perspectives for fundamental understanding and new design of functional luminescent materials (e.g., GQDs, graphene oxide, carbon dots) for imaging, sensing, and light harvesting.
View less >
View more >Graphene quantum dots (GQDs) are emerging luminescent nanomaterials for energy, bioimaging, and optoelectronic applications. However, unlike conventional fluorophores, GQDs contain multiple emissive centers that result in a complex interaction with external electromagnetic fields. Here we utilize core–shell plasmonic nanoparticles to simultaneously enhance and modulate the photoluminescence (PL) intensities and spectral profiles of GQDs. By analyzing the spectral profiles, we show that the emissive centers are highly influenced by the proximity to the metal particles. Under optimal spacer thickness of 25 nm, the overall PL displays a four-fold enhancement compared with a pristine GQD. However, detailed lifetime measurements indicate the presence of midgap states that act as the bottleneck for further enhancement. Our results offer new perspectives for fundamental understanding and new design of functional luminescent materials (e.g., GQDs, graphene oxide, carbon dots) for imaging, sensing, and light harvesting.
View less >
Journal Title
Journal of Physical Chemistry Letters
Volume
8
Subject
Physical sciences
Chemical sciences
Nanotechnology not elsewhere classified