0000000001056759

AUTHOR

Pierre Lefebvre

showing 4 related works from this author

Les politiques familiales en France et au Québec

1987

International audience

Politique familialeComparaison internationale[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/EducationFranceComputingMilieux_MISCELLANEOUSQuébec
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Optical properties and microstructure of 2.02-3.30 eV ZnCdO nanowires: effect of thermal annealing

2013

International audience; ZnCdO nanowires with up to 45% Cd are demonstrated showing room temperature photoluminescence (PL) down to 2.02 eV and a radiative efficiency similar to that of ZnO nanowires. Analysis of the microstructure in individual nanowires confirms the presence of a single wurtzite phase even at the highest Cd contents, with a homogeneous distribution of Cd both in the longitudinal and transverse directions. Thermal annealing at 550 C yields an overall improvement of the PL, which is blue-shifted as a result of the homogeneous decrease of Cd throughout the nanowire, but the single wurtzite structure is fully maintained.

010302 applied physicsTelecomunicacionesPhotoluminescenceMaterials sciencePhysics and Astronomy (miscellaneous)Annealing (metallurgy)business.industryWide-bandgap semiconductorNanowire02 engineering and technology021001 nanoscience & nanotechnologyMicrostructure01 natural sciencesHomogeneous distributionRadiative efficiency0103 physical sciences[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Optoelectronics0210 nano-technologybusinessWurtzite crystal structure
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VIS-UV ZnCdO/ZnO multiple quantum well nanowires and the quantification of Cd diffusion.

2014

International audience; We report on the growth and microstructure analysis of high Cd content ZnCdO/ZnO multiple quantum wells (MQW) within a nanowire. Heterostructures consisting of ten wells with widths from 0.7 to 10nm are demonstrated, and show photoluminescence emissions ranging from 3.03 to 1.97eV. The wells with thicknesses⩽2nm have high radiative efficiencies compared to the thickest ones, consistent with the presence of quantum confinement. However, a nanometric analysis of the Cd profile along the heterostructures shows the presence of Cd diffusion from the ZnCdO well to the ZnO barrier. This phenomenon modifies the band structure and the optical properties of the heterostructure, an…

PhotoluminescenceMaterials sciencebusiness.industryMechanical EngineeringNanowireBioengineeringHeterojunctionGeneral ChemistryMicrostructureMechanics of MaterialsQuantum dotRadiative transfer[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]OptoelectronicsGeneral Materials ScienceElectrical and Electronic EngineeringDiffusion (business)businessElectronic band structure
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Compensation verticale et compensation horizontale pour les familles avec enfants : une comparaison des approches française et québécoise

1986

International audience; L'analyse des politiques familiales demande que l'on ait au préalable défini les objectifs potentiels de ces politiques. Ceux-ci sont discutés en termes de compensation verticale, de compensation horizontale positive et compensation horizontale normative. Dans le cadre d'une politique familiale et de son influence sur la natalité, l'efficacité des techniques mises en œuvre ne peut être appréciée qu'un retard de l'importance relative accordée aux conceptions sociales de la compensation des charges familiales. L'étude identifie les différences systématiques entre la France et le Québec relativement à la politique familiale ; ce qui conduit à caractériser avec précision…

EfficacitéPolitique familialeComparaison internationaleAide à la famille[SHS.EDU]Humanities and Social Sciences/EducationCompensation verticale[SHS.EDU] Humanities and Social Sciences/EducationCompensation horizontaleFranceQuébec
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