A5073392289- 2D Materials and Applications
- Perovskite Materials and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- nanoparticles nucleation surface interactions
- Plasmonic and Surface Plasmon Research
- Chalcogenide Semiconductor Thin Films
- MXene and MAX Phase Materials
- Graphene research and applications
- Photorefractive and Nonlinear Optics
- Photonic and Optical Devices
- Advanced Fiber Laser Technologies
- Nonlinear Optical Materials Studies
- Advanced Thermodynamics and Statistical Mechanics
- Quantum Dots Synthesis And Properties
- Optical Coatings and Gratings
- Nanowire Synthesis and Applications
- Advanced Chemical Physics Studies
- Nanomaterials and Printing Technologies
- Laser-Ablation Synthesis of Nanoparticles
- Fluid Dynamics and Thin Films
- Molecular Junctions and Nanostructures
Italian Institute of Technology
2023
University of Genoa
2018-2022
Rice University
2022
Chemnitz University of Technology
2022
Superconducting and other Innovative Materials and Devices Institute
2022
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2018
Ellipsometry of hot gold nanoparticles reveals deviations their optical properties from expectations due to temperature-induced surface effects.
Excitons dominate the light absorption and re-emission spectra of monolayer transition-metal dichalcogenides (TMD). Microscopic investigations excitonic response in TMD almost invariably extract information from radiative recombination step, which only constitutes one part picture. Here, by exploiting imaging spectroscopic ellipsometry (ISE), we investigate spatial dependence dielectric function chemical vapor deposition (CVD)-grown WS2 flakes with a microscopic lateral resolution, thus...
Silver is an extremely appealing metal for plasmonics due to its very low optical losses in the visible and near-ultraviolet range relatively reactivity. Within emerging field of thermoplasmonics, where light-metal interactions are exploited generate heat on nanometric scale, knowledge temperature-dependent complex permittivities plasmonic materials indispensable. We extracted permittivity silver ${\ensuremath{\varepsilon}}_{Ag}$ by spectroscopic ellipsometry under high-vacuum conditions....
The excitation of plasmonic nanoparticles by ultrashort laser pulses sets in motion a complex ultrafast relaxation process involving the gradual re-equilibration system's electron gas, lattice, and environment. One major hurdles studying these processes is lack direct measurements dynamic temperature evolution system subcomponents. We measured optical response ensembles Au following ultra-short-pulse excitation, we compared it with corresponding static as function increasing thermodynamic...
The electromagnetic field confinement and amplification typical of nano-sized metallic objects supporting localized surface plasmon resonances, i.e., light-induced collective electronic oscillations, can significantly strengthen the interaction light with atomically thin transition metal dichalcogenides. In view realization plasmon-enhanced devices, it is crucial to investigate effects induced by within nanostructures on excitonic properties these materials at nanoscale. Here, we exploit...
Heterostacks composed of two-dimensional WS2 and graphene exhibit interesting opto-electronic properties, including ultrafast charge transfer fast, efficient photodetection. The optical properties are heavily influenced by the presence in heterostack, yet, so far, their characterization whole visible range is missing. In this work we report complex dielectric function flakes on epitaxial silicon carbide, obtained means spectroscopic ellipsometry (SE). so-called A, B C excitonic features...
Abstract The opto‐electronic properties of semiconducting 2D materials can be flexibly manipulated by engineering the atomic‐scale environment. This done including in tailored van der Waals (vdW) stacks, whose optical response is a function number and type adjacent layers. work reports systematic investigation dielectric WS 2 various stacking configurations: monolayer, 3R/2H homobilayer, /MoS heterobilayer. Reliable, Kramers–Kronig‐consistent functions are obtained for each configuration...
Monolayer tungsten disulfide (WS2) has recently attracted a great deal of interest as promising material for advanced electronic and optoelectronic devices such photodetectors, modulators, sensors. Since these can be integrated in silicon (Si) chip via back-end-of-line (BEOL) processes, the stability monolayer WS2 BEOL fabrication conditions should studied. In this work, thermal single-crystal at typical is investigated; namely (a) heating temperature 300 °C, (b) pressures medium- (10−3...
Abstract The femtosecond evolution of the electronic temperature laser‐excited gold nanoparticles is measured, by means ultrafast time‐resolved photoemission spectroscopy induced extreme‐ultraviolet radiation pulses. electron gas deduced recording and fitting high‐resolution photo emission spectra around Fermi edge providing a direct, unambiguous picture electron‐gas dynamics. These results will be instrumental to refinement existing models processes in laterally‐confined bulk...
Hexagonal boron nitride (hBN), sometimes referred to as white graphene, receives growing interest in the scientific community, especially when combined into van der Waals (vdW) homo- and heterostacks, which novel interesting phenomena may arise. hBN is also commonly used combination with two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDCs). The realization of hBN-encapsulated TMDC heterostacks can indeed offer opportunities investigate compare excitonic properties...
The combination of metallic nanostructures with two-dimensional transition metal dichalcogenides is an efficient way to make the optical properties latter more appealing for opto-electronic applications. In this work, we investigate monolayer WS2 flakes grown by chemical vapour deposition and transferred onto a densely-packed array plasmonic Au nanoparticles (NPs). response was measured as function thickness dielectric spacer intercalated between two materials system temperature, in 75–350 K...
Silver represents, by and large, the best plasmonic metal available, due to its very low optical losses in a broad photon-energy range encompassing all visible spectrum. Its performances are, more often than not, severely hampered presence of few-nanometer thick surface-tarnish layer; thermal annealing under high-vacuum (HV) conditions may however lead decomposition, thereby allowing attain clean-metal response. Here, we report an experimental investigation temperature dependence response Ag...
We report the design and fabrication of lithium niobate nanostructured resonators for directional beaming spontaneous parametric down-conversion. Preliminary measurements achieved photon-pair production rates up to 300 Hz/W at telecom wavelengths.
Monolayer tungsten disulfide ($WS_2$) has recently attracted large interest as a promising material for advanced electronic and optoelectronic devices such photodetectors, modulators, sensors. Since these can be integrated in silicon (Si) chip via back-end-of-line (BEOL) processes, the stability of monolayer $WS_2$ BEOL fabrication conditions should studied. In this work, thermal single-crystal at typical is investigated; namely (i) heating temperature $300$ $^\circ C$, (ii) pressures...
Abstract We report a real time, in-situ spectroscopic ellipsometry study of the temperature-induced solid-state dewetting Au nanowires into nanoparticles. Very large spectral variations are observed at different temperatures. Analysis key features in acquired spectra reveals two regimes: up to 300 °C variation optical response is dominated by dewetting, while above that temperature, smaller not compatible with such mechanism visible. Therefore our measurements allow us determine time which...
Lithium niobate (LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) is a prime material for photonics thanks to unique mix of properties, including strong electro-optical and nonlinear optical responses as well broad transparency window spanning the visible near-infrared (NIR) range (0.35 4.5 μm). Despite inherent challenges in nanofabrication LiNbO , caused by its hardness resistance chemical etching, recent technical advances...