Harnessing Colloidal Plasmonic Metasurfaces for Advanced Optical Phenomena
Date: Tuesday, 4 June 2024
Time: 11AM
Venue: Institut de Ciència de Materials de Barcelona (ICMAB, CSIC) - Sala d'Actes Carles Miravitlles
Abstract:
Photonic metasurfaces are artificial structures that generate unique electromagnetic responses emerging from the spatial arrangements of their subwavelength components, offering exceptional flexibility for the manipulation of light-matter interactions. For example, by varying the geometrical parameters of ordered arrays composed of plasmonic nanoparticles, it is possible to engineer collective surface lattice plasmon resonances (SLRs) that can be tuned from the UV to the IR. This tunability in design can be exploited for the enhancement of nonlinear optical phenomena such as lasing emission, strong coupling or second harmonic generation. Recently, the focus of the metamaterial community has turned to the design of chemically active devices that can interact with the surrounding chemical space, a shift that calls for new fabrication methodologies that can overcome the limitations imposed by standard hard-lithography processing. The use of colloidal building blocks for the bottom-up fabrication of optical metasurfaces represents a great step in this direction, taking advantage of the unmatched level of control over nanoparticle morphology, crystallography, composition, and surface chemistry.
In this thesis work, we optimized two methodologies for the fabrication of colloidal plasmonic metasurfaces: template-assisted self-assembly, organizing pre-synthesized colloidal building blocks using elastomeric stamps, and chemical contrast in situ growth, where plasmonic nanostructures are grown into predetermined patterns directly on substrates. My work shows how colloidal plasmonic metasurfaces, used as free-labelled and accessible optical cavities, can provide the optical quality required to enable the enhancement of both linear and nonlinear optical phenomena. In the long run, the collected results highlight the potential of colloidal-based plasmonic metasurfaces as candidates for delving in a wide range of applications, including photocatalysis, biosensing, and energy harvesting.
Supervisor:
Leonardo Scarabelli
PhD comitee:
President: Prof. Lucia Curri, CNR-IPCF Bari Division, Università degli Studi di Bari Aldo Moro, Italy.
Secretary: Prof. Alejandro Rodolfo Goñi, Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Spain.
Vocal: Prof. Yuri Antonio Diaz Fernandez, InLAB, Università degli studi di Pavia, Italy.
University: Universitat Autònoma de Barcelona (UAB)
PhD Programme: Material Science
