Show simple item record

dc.contributor.authorCosentino, S.en_US
dc.contributor.authorMio, A. M.en_US
dc.contributor.authorBarbagiovanni, E. G.en_US
dc.contributor.authorRaciti, R.en_US
dc.contributor.authorBahariqushchi, R.en_US
dc.contributor.authorMiritello, M.en_US
dc.contributor.authorNicotra, G.en_US
dc.contributor.authorAydinli, A.en_US
dc.contributor.authorSpinella, C.en_US
dc.contributor.authorTerrasi, A.en_US
dc.contributor.authorMirabella, S.en_US
dc.date.accessioned2016-02-08T10:06:26Z
dc.date.available2016-02-08T10:06:26Z
dc.date.issued2015en_US
dc.identifier.issn2040-3364
dc.identifier.urihttp://hdl.handle.net/11693/22913
dc.description.abstractQuantum confinement (QC) typically assumes a sharp interface between a nanostructure and its environment, leading to an abrupt change in the potential for confined electrons and holes. When the interface is not ideally sharp and clean, significant deviations from the QC rule appear and other parameters beyond the nanostructure size play a considerable role. In this work we elucidate the role of the interface on QC in Ge quantum dots (QDs) synthesized by rf-magnetron sputtering or plasma enhanced chemical vapor deposition (PECVD). Through a detailed electron energy loss spectroscopy (EELS) analysis we investigated the structural and chemical properties of QD interfaces. PECVD QDs exhibit a sharper interface compared to sputter ones, which also evidences a larger contribution of mixed Ge-oxide states. Such a difference strongly modifies the QC strength, as experimentally verified by light absorption spectroscopy. A large size-tuning of the optical bandgap and an increase in the oscillator strength occur when the interface is sharp. A spatially dependent effective mass (SPDEM) model is employed to account for the interface difference between Ge QDs, pointing out a larger reduction in the exciton effective mass in the sharper interface case. These results add new insights into the role of interfaces on confined systems, and open the route for reliable exploitation of QC effects. © The Royal Society of Chemistry.en_US
dc.language.isoEnglishen_US
dc.source.titleNanoscaleen_US
dc.relation.isversionofhttp://dx.doi.org/10.1039/c5nr01480hen_US
dc.subjectAbsorption spectroscopyen_US
dc.subjectChemical analysisen_US
dc.subjectElectromagnetic wave absorptionen_US
dc.subjectElectron energy levelsen_US
dc.subjectElectron energy loss spectroscopyen_US
dc.subjectElectron scatteringen_US
dc.subjectEnergy dissipationen_US
dc.subjectGermaniumen_US
dc.subjectGermanium oxidesen_US
dc.subjectLight absorptionen_US
dc.subjectMagnetron sputteringen_US
dc.subjectNanostructuresen_US
dc.subjectPlasma enhanced chemical vapor depositionen_US
dc.subjectQuantum confinementen_US
dc.subjectSemiconductor quantum dotsen_US
dc.subjectConfined systemsen_US
dc.subjectElectrons and holesen_US
dc.subjectGermanium quantum dotsen_US
dc.subjectNanostructure sizeen_US
dc.subjectOscillator strengthsen_US
dc.subjectPlasma enhanced chemical vapor depositions (PE CVD)en_US
dc.subjectQuantum confinement effectsen_US
dc.subjectrf-Magnetron sputteringen_US
dc.subjectInterface statesen_US
dc.titleThe role of the interface in germanium quantum dots: when not only size matters for quantum confinement effectsen_US
dc.typeArticleen_US
dc.departmentDepartment of Physics
dc.citation.spage11401en_US
dc.citation.epage11408en_US
dc.citation.volumeNumber7en_US
dc.identifier.doi10.1039/c5nr01480hen_US
dc.publisherRoyal Society of Chemistryen_US
dc.identifier.eissn2040-3372


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record