At Lecce Unit there is a long time experience in both the Synthesis and the Advanced Characterization techniques applied to Functional Nanomaterials.
Synthesis of Advanced Nanostructured Materials
Metalorganic Vapour Phase Epitaxy (MOVPE) growth technology of III-V compound semiconductor nanowires by self-assembly processes and selective area epitaxy for application in the fields of Energy conversion (high efficiency photovoltaic cells) and Photonics (nano-laser, photo-detectors): (i) core-shell and core-multishell nanowires with “quantum-well tube” structure based on III-V materials, and (ii) core-shell nanowires based on III-N-V intermediate band.
FE-SEM micrographs of three different NW structures, namely (a) GaAs, (b) GaAs/AlGaAs core-shell and AlGaAs NWs. Markers in (a) are for all images and represent 2 micron. The insets show the corresponding in-plane morphology (cross-sectional shape) of a single NW [MRS Symp. Procs., vol. 1350, Paper no.: 1350-EE06-01 (2011)]
Van der Waals epitaxy by means of Molecular Beam Epitaxy (MBE) of 2-dimensional (‘layered’) materials, such as graphene and graphene-like materials (Transition Metal Dichalcogenides, TMDC and hexagonal boron nitride, h-BN) for energy applications (high efficiency photovoltaic cells) and nano-electronics applications (transistors, tunnel diodes). The MBE technology for the growth of such materials – unique in Italy - has been chosen to get high structural quality and purity materials in order to increase their optical and electronic properties.
Contact person: Paola Prete
Sol-gel/solvothermal synthesis of colloidal oxide nanostructures in energy conversion/storage systems: copper oxide (CuO) nanocrystals as active components in nanofluids for enhancing the heat exchange in solar concentrator systems; supercapacitor application of colloidal TiO2-V2O5 nanocrystals; application of SnO2-V2O5 and TiO2-V2O5 nanocrystals as cathodes for lithium batteries and in artificial photosynthesis (CO2 reduction), photocatalysis.
HRTEM image of copper sulphide nanocrystals prepared by solvothermal synthesis
Contact person: Mauro Epifani
Advanced Characterization for the investigation/manipulation of Functional Nanostructured Materials
In the frame of the advanced optical, electro-optical and magneto-plasmonic characterization activity of nanostructured materials for different application areas, unconventional and not commercially available experimental setups have been developed. These techniques are applied to the investigation of the physical and chemical properties of a large class of nanostructured systems such as: a) GaN/AlGaN superlattice, InAs/GaAs, InAs/AlGaAs Quantum Dots (NANOTEC-CNR Lecce); b) InGaAs/GaAs doped quantum dots (IMEM-CNR Parma); c) GaAs/AlGaAs and CdTe nanowires (University of Salento Lecce PHASHYN & INNOVASOL Projects) ; d) metal oxide nanoparticles for air based nanofluid in thermodynamic solar power plant (PON SOLAR & INNOVASOL projects); e) other nanostructured materials for plasmonic and photonics applications (functionalized gold, nichel, silver nanoparticles, nanodisks, multilayers nanodisks, nanorods and so on, prepared onto large area 2D and 3D transducers).