Surface Science of Plasmonic Materials

DIPC Seminars

Speaker

Andrew P. Weber
University of Missouri-Kansas City

When

2025/03/28
12:00

Place

DIPC Seminar Room

Host

Enrique Ortega

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The ability to confine, guide, and mix light at the nanoscale is critical for the future development of optical sensing, optical communications and computing, photovoltaic, and other technologies. Plasmonics can play a significant role in this development, because it provides a means of enhancing the optical response of materials through the local amplification of electric fields by surface plasmon resonances. A scalable strategy for obtaining plasmonic nanostructures exists in the growth and stabilization of Ag films on patterned Si substrates, producing resonances observed in the 1-4 μm excitation wavelength range1. After summarizing the physics and applications of plasmonics, I will describe the surface-science-based approach to the fabrication and characterization of the Ag/Si nanomaterials, which includes electron beam lithography, molecular beam epitaxy, low energy electron diffraction, angle-resolved photoemission spectroscopy, X-ray photoelectron spectroscopy, scanning tunneling microscopy, and Fourier transform infrared spectroscopy methods. The cleanliness of the substrate and introduction of a surface diffusion barrier are shown to be crucial for long-term stability and flatness of the Ag/Si film. Finally, I will describe how engineering the electronic band structure (observed by angle-resolved photoemission spectroscopy) in layered anisotropic materials like (Mo/W)Te2 [2], opens new avenues in nonlinear plasmonics.

References:
1. V. Mkhitaryan, A.P. Weber et al. “Ultraconfined Plasmons in Atomically Thin Crystalline Silver Nanostructures” Advanced Materials, 36 (9), 2302520 (2024)
2. A.P. Weber et al. “Spin-resolved electronic response to the phase transition in MoTe2” Physical Review Letters, 121, 156401 (2018)