Search results for " quantum confinement"

showing 2 items of 2 documents

Luminescence Efficiency of Si/SiO 2 Nanoparticles Produced by Laser Ablation

2019

Photoluminescence properties of Si(core)/SiO 2 (shell) nanoparticles produced by pulsed laser ablation in aqueous solution are investigated with the purpose to highlight the microscopic processes that govern the emission brightness and stability. Time resolved spectra evidence that these systems emit a µs decaying band centered around 1.95 eV, that is associated with the radiative recombination of quantum-confined excitons generated in the Si nanocrystalline core. Both the quantum efficiency and the stability of this emission are strongly dependent on the pH level of the solution, that is changed after the laser ablation is performed. They enhance in acid environment because of the H + pass…

PhotoluminescenceLaser ablationMaterials scienceSi/SiO2 nanoparticles pulsed laser ablation quantum confinement luminescence IR absorption pH dependencebusiness.industry2Surfaces and InterfacesCondensed Matter Physicslaser ablation; pH dependence; photoluminescence; quantum confinement; Si/SiO ; 2; nanoparticlesquantum confinementSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsQuantum dotSio2 nanoparticleslaser ablationMaterials ChemistryPh dependenceOptoelectronicsphotoluminescencenanoparticlespH dependenceElectrical and Electronic EngineeringLuminescencebusinessSi/SiOphysica status solidi (a)
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Quantum confinement effects observed by the photoluminescence of SiOx/SiO2 multilayers

2012

Spectral and decay features related to the red emission from Si nanocrystals were investigated by time-resolved photoluminescence spectra carried out on SiOx/SiO2 nanosized multilayers. On decreasing the SiOx thickness from 8.4 nm to 2.2 nm this luminescence band exhibits a blue-shift from 1.65 eV to 1.75 eV and its lifetime increases from 12μs to 17 μs. These results are discussed on the basis of previous models proposed in literature and agree with quantum confinement effects arising from differently sized Si nanocrystals in our samples.

SiOx/SiO2 mulilayers Si nanocrystal quantum confinement time-resolved photoluminescence
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