Publications by authors named "Matteo Barelli"
Heavy-metal-free III-V colloidal quantum dots (QDs) exhibit promising attributes for application in optoelectronics. Among them, InAs QDs are demonstrating excellent optical performance with respect to absorption and emission in the near-infrared spectral domain. Recently, InAs QDs attained a substantial improvement in photoluminescence quantum yield, achieving 70% at a wavelength of 900 nm through the strategic overgrowth of a thick ZnSe shell atop the InAs core.
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- Following defocused ion beam sputtering, highly corrugated and faceted nanoripples form on calcite surfaces in a self-organized manner.
- High-resolution atomic force microscopy (AFM) shows that these ripples consist of intricate facets that become smoother upon exposure to PbClaqueous solution, facilitating lead uptake.
- Analysis indicates a significant 500% increase in lead absorption rate on nanostructured calcite compared to fresh surfaces, suggesting potential applications for lead removal in contaminated water systems.
The controlled placement of colloidal semiconductor nanocrystals (NCs) onto planar surfaces is crucial for scalable fabrication of single-photon emitters on-chip, which are critical elements of optical quantum computing, communication, and encryption. The positioning of colloidal semiconductor NCs such as metal chalcogenides or perovskites is still challenging, as it requires a nonaggressive fabrication process to preserve the optical properties of the NCs. In this work, periodic arrays of 2500 nanoholes are patterned by electron beam lithography in a poly(methyl methacrylate) (PMMA) thin film on indium tin oxide/glass substrates.
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- Novel methods for light harvesting are essential for developing renewable energy technologies to tackle global environmental challenges.
- Two-dimensional transition metal dichalcogenide (TMD) semiconductor layers show promise for these applications, but their low photon absorption necessitates innovative designs.
- The proposed strategy involves ultra-thin MoS layers on patterned templates that enhance photon confinement, leading to more efficient photodissociation of pollutants like methylene blue and improved energy conversion efficiency in various applications.
Advances in surface chemistry of CsPbX (where X = Cl, Br or I) nanocrystals (NCs) enabled the replacement of native chain ligands in solution. However, there are few reports on ligand exchange carried out on CsPbX NC thin films. Solid-state ligand exchange can improve the photoluminescence quantum yield (PLQY) of the film and promote a change in solubility of the solid surface, thus enabling multiple depositions of subsequent nanocrystal layers.
View Article and Find Full Text PDFFlat optics nanogratings supported on thin free-standing membranes offer the opportunity to combine narrowband waveguided modes and Rayleigh anomalies for sensitive and tunable biosensing. At the surface of high-refractive index SiN membranes we engineered lithographic nanogratings based on plasmonic nanostripes, demonstrating the excitation of sharp waveguided modes and lattice resonances. We achieved fine tuning of these optical modes over a broadband Visible and Near-Infrared spectrum, in full agreement with numerical calculations.
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- Bidirectional nanoantennas enable advanced functions at the nanoscale, particularly for color routing in compact optical systems.
- The new approach uses a simpler bimetallic structure to create effective nanoantennas without complex designs, employing a self-organized technique for large-area fabrication.
- The developed nanoantennas show impressive performance in broadband color routing and light scattering, making them viable for applications in telecommunications and optical sensing.