Photoluminescence of Carbon Dots Embedded in a SiO2 Matrix
- Autori: Messina, F.; Sciortino, L.; Buscarino, G.; Agnello, S.; Gelardi, F.; Cannas, M.
- Anno di pubblicazione: 2016
- Tipologia: Articolo in rivista (Articolo in rivista)
- Parole Chiave: Carbon dots; Photoluminescent nanocarbons; Photoluminescent silica monolith; Time-resolved photoluminescence; Materials Science (all)
- OA Link: http://hdl.handle.net/10447/179375
We synthetized carbon dots by a pyrolitic method, and studied their photoluminescence in aqueous environment and upon trapping in a solid matrix. To this aim, we devised a facile procedure allowing to embed the dots in amorphous SiO2, without the need of any pre-functionalization of the nanoparticles, and capable of yielding a brightly photoluminescent monolith. Experimental data reveal a remarkable similarity between the emission properties of carbon dots in water and in SiO2, suggesting that the chromophores responsible of the photoluminescence undergo only weak interactions with the environment. Time-resolved photoluminescence data reveal that the typical photoluminescence tunability of these dots mostly arises, in the present case, from the co-existence of two independent emission bands. These two signals have different emission peak positions (2.8-2.9 and 2.2-2.3 eV respectively) and decay lifetimes (7.0 and 9.0 ns respectively), while their intensity ratio is controlled by the excitation wavelength.