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Welcome to the NanoStructures Group (NSG) Website.

NSG research group is located at Dept. of Physics and Astronomy (DFA) of the Padua University, in Padua, Italy.

Its research activity is focused on nanoscience and nanotechnology involving advanced nanostructures for applications in nanophotonics, quantum technologies and catalysis.

Combining competencies in physics and materials science, NSG investigates matter at the nanoscale spanning from nanofabrication, to characterization and modeling of innovative functional nanostructures and metamaterials.

Due to the quantum confinement, at the nanoscale materials properties depend on their size.

Thus, controlling the nanostructure size, morphology and degree of mutual interaction, it is possible to obtain novel properties that are interesting not only from the viewpoint of basic physics research but also for their relevant technological applications.

NSG Research Areas

The control and manipulation of light beams at the nanoscale is one of the main requirements for many advanced applications in free-space and integrated photonics and quantum optics, as for example for the development of single-photon sources and coherent nanosources (nanolasers). Consequently, the design and fabrication of novel nanostructured materials able to satisfy this demand has become one of the greatest challenges for nanophotonics.
Some of the investigated topics:
* Single-photon emitters
* Nanolasers
* Emitter-Nanostructures interaction for controlling the emission quantum efficiency
* Energy transfer processes between emitters and plasmonic nanostructures

Metamaterials (MMs) are artificially nanostructured materials whose optical functionalities go beyond ("meta") those of their elementary constituents, and which can be engineered by properly controlling the properties and the coupling of the functional nanometric building-blocks on a sub-wavelength scale. At NSG we investigate:
* MMs with hyperbolic optical dispersion
* Epsilon-Near Zero (ENZ) MMs
* Time-varying MMs

When photons in the visible or near-infrared range interact with metallic nanostructures whose size, shape and composition (e.g., Au or Ag or their alloys) suitably designed to exploit the surface plasmon resonance phenomenon, it becomes possible to localize the electromagnetic field intensity in sub-wavelength regions (surpassing the diffraction limit) or to exploit peculiar phenomena working at the nanoscale such as the extraordinary optical transmission from ordered arrays of n anohole with sub-wavelength diameter) in a thin plasmonic film. Some investigated topics:
* Linear and nonlinear optical properties of metal nanostructures
* Plasmonic bio-sensors
* Modeling of the plasmonic properties of isolated or interacting nanostructures

Photocatalysis is one of the most interesting processes for promoting chemical reactions due to its use of solar energy. The ability of plasmonic nanostructures to focus light and to locally amplify its intensity is extremely relevant when coupled to nanostructures of semiconducting oxides, allowing to control the injection of hot carriers activated during plasmonic resonances. Some investigated topics:
* High-surface area nanostructures of Co and Fe for electro-photocatalysis
* Photo-Catalysis
* Water remediation

The control of the surface properties in terms of hydrophobicity, conductivity or morphology allows the use of such chemically and/or morphologically patterned surfaces as an 'active' substrate to control dynamics of fluids above or more complex processes, like cell growth. Patterning can be achieved by (atmospheric) plasma or ion implantation. Some investigated topics:
* Thermodynamics of nucleation and growth
* Nano-alloying of immiscible elements by ion implantation
* Ion beam induced selective de-alloying
* Atmospheric Plasma treatments for chemical/morphological surface modification
* Nano- and Micro-patterned surfaces for cellular growth