We reported the synthesis of silicon nanoparticles with mean size varying from 60 nm to 3 nm, by ultrafast laser ablation of a silicon target in deionized water. Optical absorption, Raman spectroscopy and Electron microscopy were performed to characterize the nanoparticles. The crystalline structure of the obtained silicon nanoparticles was confirmed with Raman spectroscopy combined with High resolution transmission electronic microscopy. The energy confinement of carriers which is evaluated from optical experiments varies from 90 meV to 440 meV when the mean nanoparticles size decreases from 60 nm to 3 nm. In particular, the evaluated nanoparticles size from optical analysis and LCAO theoretical model are found in agreement with Transmission Electron Microscopy and Raman measurements for the silicon nanoparticles with a size less than 6 nm. Finally, we studied the stability of silicon nanoparticles with time which demonstrates that the smallest nanoparticle aggregates over time.
Optical characterization of silicon nanoparticle obtained via femtosecond laser ablation in deionized water
DIASPRO, ALBERTO GIOVANNI
2011-01-01
Abstract
We reported the synthesis of silicon nanoparticles with mean size varying from 60 nm to 3 nm, by ultrafast laser ablation of a silicon target in deionized water. Optical absorption, Raman spectroscopy and Electron microscopy were performed to characterize the nanoparticles. The crystalline structure of the obtained silicon nanoparticles was confirmed with Raman spectroscopy combined with High resolution transmission electronic microscopy. The energy confinement of carriers which is evaluated from optical experiments varies from 90 meV to 440 meV when the mean nanoparticles size decreases from 60 nm to 3 nm. In particular, the evaluated nanoparticles size from optical analysis and LCAO theoretical model are found in agreement with Transmission Electron Microscopy and Raman measurements for the silicon nanoparticles with a size less than 6 nm. Finally, we studied the stability of silicon nanoparticles with time which demonstrates that the smallest nanoparticle aggregates over time.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.