233 research outputs found
Marriage record of Di Giorgio, Giuseppe and Zambito, Pellegrina
No full textMarriage license for Giuseppe Di Giorgio and Pellegrina Zambito. Philip F. Licata was the Notary Public
Scalable and Deterministic Nanofabrication of Hybrid 2D Transition Metal Dichalcogenide Layers for Light Manipulation and Energy Harvesting
No full textTwo-dimensional (2D) materials, and in particular Transition Metal Dichalcogenides (TMDs), have attracted significant interest as potential alternatives to silicon for future nanoelectronic and optoelectronic technologies, thanks to their unique electronic and optical properties. However, the practical implementation of TMDs in functional devices remains limited by several challenges, including the scalable synthesis of high-quality homogeneous films, the ability to pattern these materials with nanoscale precision, and the development of reliable, controllable doping strategies. This PhD work addresses these issues by exploring low-temperature deposition of large-area TMD films via Ion Beam Sputtering (IBS) and subsequent possibility to induce recrystallization via high-temperature processes. In parallel, it introduces thermal Scanning Probe Lithography (t-SPL) as a novel and minimally invasive nanofabrication technique, capable of locally tuning the optoelectronic properties of TMDs with high spatial resolution. The results presented here offer new perspectives for the integration of 2D materials into scalable, next-generation device architectures
Controlling resonant surface modes by arbitrary light induced optical anisotropies
Get PDFIn this work the sensitivity of Bloch Surface Waves to laser-induced anisotropy of azo-polymeric thin layers is expe rimentally shown . The nanoscale reshaping of the films via thermal-Scanning Probe Lithography allows to couple light to circular photonic nanocavities, tailoring on-demand resonant BSW confined within the nanocavity
Bloch Surface Waves in Resonant Structures
Get PDFIn this work, we make a step forward in the manipulation of light on the surface of one-dimensional photonic crystal through Bloch Surface Waves (BSW) within resonant structures of various types. Linear Fabry-Perot cavities eventually combined with diffraction gratings allow to directly couple BSW from free-space radiation. Design, fabrication and experimental characterization are provided
Spectral tuning of Bloch Surface Wave resonances by light-controlled optical anisotropy
Get PDFFostered by the recent advancements in photonic technologies, the need for all-optical dynamic control on complex photonic elements is emerging as more and more relevant, especially in integrated photonics and metasurface-based flat-optics. In this framework, optically-induced anisotropy has been proposed as powerful mean enabling tuning functionalities in several planar architectures. Here, we design and fabricate an anisotropic
two-dimensional bull’s eye cavity inscribed within an optically-active polymeric film spun on a one-dimensional photonic crystal sustaining Bloch surface waves (BSW). Thanks to the cavity morphology, two surface resonant modes with substantially orthogonal polarizations can be
coupled within the cavity from free-space illumination. We demonstrate that a dynamic control on the resonant mode energies can be easily operated by modulating the orientation of the optically-induced birefringence on the surface, via a polarized external laser beam. Overall, reversible
blue- and red-shifts of the resonant BSWs are observed within a spectral range of about 2 nm, with a moderate laser power illumination. The polymeric structure is constituted by a novel blend of an azopolymer and a thermally-sensitive resist, which allows a precise patterning
via thermal scanning probe lithography, while providing a significant structural integrity against photo-fluidization or mass-flow effects commonly occurring in irradiated azopolymers. The proposed approach based on tailored birefringence opens up new pathways to finely control the
optical coupling of localized surface modes to/from free-space radiation, particularly in hybrid organic–inorganic devices
Flat-optics hybrid MoS2/polymer films for photochemical conversion
No full textNovel light harvesting platforms and strategies are crucial to develop renewable photon to energy conversion technologies that overcome the current global energy and environmental challenges. Two-dimensional (2D) transition metal dichalcogenide (TMD) semiconductor layers are particularly attractive for photoconversion applications but new ultra-compact photon harvesting schemes are urgently required to mitigate their poor photon absorption properties. Here, we propose a flat-optics scheme based on nanogrooved ultra-thin MoS2 layers conformally grown onto large area (cm2 scale) nanopatterned templates. The subwavelength re-shaping of the 2D-TMD layers promotes the excitation of photonic Rayleigh anomaly (RA) modes, uniquely boosting a strong in-plane electromagnetic confinement. By tailoring the illumination conditions, we demonstrate effective tuning of the photonic anomalies over a broadband visible spectrum across the absorption band of relevant polluting dye molecules. Thanks to the strong photonic in-plane confinement, we achieve a resonant enhancement of the photodissociation rate of methylene blue (MB) molecules, well above a factor of 2. These results highlight the potential of flat-optics photon harvesting schemes for boosting photoconversion efficiency in large-scale hybrid 2D-TMD/polymer layers, with a strong impact in various applications ranging from new-generation photonics to waste water remediation and renewable energy storage
Large-area and nanopatterned 2D-TMD heterostructures for improved visible-light photoconversion
No full textLarge area nanostructuring of van der Waals materials for photon harvesting in the flat optics regime
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