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RESEARCH PRODUCT
Self-limiting and complete oxidation of silicon nanostructures produced by laser ablation in water
Reinhard SchneiderFranco Mario GelardiMarco CannasDagmar GerthsenRadian PopescuFabrizio MessinaLavinia VaccaroP. Camardasubject
Silicon nanocrystal Silica nanoparticles laser ablation Time resolved phtoluminescence High resolution transmission electron microscopy Silicon Oxidation Quantum Confinment DefectsMaterials scienceLaser ablationPhotoluminescenceSiliconSettore FIS/01 - Fisica SperimentaleAnalytical chemistryGeneral Physics and Astronomychemistry.chemical_element02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesAmorphous solidNanomaterialschemistry0210 nano-technologyLuminescenceSpectroscopyTunable laserdescription
Oxidized Silicon nanomaterials produced by 1064 nm pulsed laser ablation in deionized water are investigated. High-resolution transmission electron microscopy coupled with energy dispersive X-ray spectroscopy allows to characterize the structural and chemical properties at a sub-nanometric scale. This analysis clarifies that laser ablation induces both self-limiting and complete oxidation processes which produce polycrystalline Si surrounded by a layer of SiO2 and amorphous fully oxidized SiO2, respectively. These nanostructures exhibit a composite luminescence spectrum which is investigated by time-resolved spectroscopy with a tunable laser excitation. The origin of the observed luminescence bands agrees with the two structural typologies: Si nanocrystals emit a μs-decaying red band; defects of SiO2 give rise to a ns-decaying UV band and two overlapping blue bands with lifetime in the ns and ms timescale.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-07-14 |