0000000000615055

AUTHOR

E. G. Barbagiovanni

showing 2 related works from this author

Size dependent light absorption modulation and enhanced carrier transport in germanium quantum dots devices

2015

Quantum confinement in closely packed arrays of Ge quantum dots (QDs) was studied for energy applications. In this work, we report an efficient tuning mechanism of the light harvesting and detection of Ge QDs. Thin films of SiGeO alloys, produced by rf-magnetron sputtering, were annealed at 600 degrees C in N-2 to induce precipitation of small amorphous Ge QDs into the oxide matrix. Varying the Ge content, the QD size was tailored between 2 and 4 nm, as measured by high resolution transmission electron microscopy. X-ray photoelectron spectroscopy (XPS) measurements indicate the formation of pure SiO2, as well as the presence of a sub-stoichiometric Ge oxide shell at the QD interface. Light …

Precipitation (chemical)Materials scienceAmorphous alloyBand gapchemistry.chemical_elementHigh resolution transmission electron microscopyPhotoconductive gainGermaniumNanocrystalMetal-insulator semiconductor deviceSettore ING-INF/01 - ElettronicaSettore FIS/03 - Fisica Della MateriaAbsorption spectroscopyQuantum confinement effectQuantum confinementElectromagnetic wave absorptionLight absorptionThin filmGermanium oxideOxide filmHigh-resolution transmission electron microscopyGermanium quantum dotPotential wellMIS deviceAmorphous filmGermaniumQuantum dotsRenewable Energy Sustainability and the Environmentbusiness.industryPhotoconductivitySolar cellPreferential trappingMIM deviceSemiconductor deviceSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsPhotovoltaicschemistryMetal insulator boundarieQuantum dotrf-Magnetron sputtering Semiconductor quantum dotOptoelectronicsCharge carrierX ray photoelectron spectroscopy Effective mass approximationbusinessQuantum chemistryPhotovoltaicMagnetron sputteringSolar Energy Materials and Solar Cells
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Photoluminescence transient study of surface defects in ZnO nanorods grown by chemical bath deposition

2015

Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (Vo) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two Vo states was found to be sensitive to the ambient environment and to NR post-growth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient, indicating a clear role of atmospheric O-2 on the surface defect states. A model fo…

PhotoluminescencePhysics and Astronomy (miscellaneous)Analytical chemistryPhotovoltaic applicationFOS: Physical scienceschemistry.chemical_elementNanorodOxygen vacancieSettore ING-INF/01 - ElettronicaOxygensymbols.namesakeMesoscale and Nanoscale Physics (cond-mat.mes-hall)ultravioletSurface defect stateDepositionPhotoluminescenceChemical-bath depositionTransient studies Surface defectsPhysicsCondensed Matter - Mesoscale and Nanoscale PhysicsFermi levelDeep-level defectBand bendingnanowireschemistryZinc oxide Ambient environmentsymbolsNanorodPhotoluminescence intensitiefilmsTransient (oscillation)Resistance measurementIntensity (heat transfer)Chemical bath depositionApplied Physics Letters
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