Earth-Abundant Layered Materials: Vibrational Properties and Optoelectronics Applications – Ingrid Barcelos, LNLS, Campinas

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Data / Hora
Date(s) - 19/10/2023
17:00 - 18:00



Earth-Abundant Layered Materials: Vibrational Properties and Optoelectronics Applications

Profa. Ingrid Barcelos, LNLS

19 de outubro de 2023 –  5a. f – 17h – L776

Phyllosilicates emerge as a promising class of large bandgap lamellar insulators. Their applications have been explored from the fabrication of graphene-based devices to two-dimensional (2D) heterostructures based on transition metal dichalcogenides with enhanced optical properties, optoelectronics, and polaritonics 1–4. Despite the extensive knowledge of the chemical composition of bulk phyllosilicates, retrieved from standard techniques such as Raman and IR spectroscopies, very little is known about those optical properties at the sub-micron spatial scale. Here, we provide an overview of IR s-SNOM for studying nano-optics and local chemistry of various 2D natural phyllosilicates including talc, phlogopite, and clinochlore2,3,5. Also, we bring a brief update on applications that combine natural minerals, graphene and phyllosilicate layers into functional heterostructures. Additionally, we show that natural 2D talc supports hyperbolic phonon-polaritons (HPhP) similarly to the well-established 2D polaritonic hBN and α-MoO3 crystals in the far- and mid-IR range. Further, we highlight a few advances regarding nano-optical modulation in graphene-phyllosilicates devices driven by electrical control.

  1. Prando, G. A. et al. Revealing Excitonic Complexes in Monolayer WS2 on Talc Dielectric. Phys Rev Appl 16, 64055 (2021).
  2. Cadore, A. R. et al. Exploring the structural and optoelectronic properties of natural insulating phlogopite in van der Waals heterostructures. 2d Mater 9, (2022).
  3. Barcelos, I. D. et al. Infrared fingerprints of natural 2D talc and plasmon-phonon coupling in graphene-talc heterostructures. ACS Photonics 5, acsphotonics.7b01017 (2018).
  4. Nutting, D. et al. Electrical and optical properties of transition metal dichalcogenides on talc dielectrics. Nanoscale 13, 15853–15858 (2021).
  5. de Oliveira, R. et al. High throughput investigation of an emergent and naturally abundant 2D material: Clinochlore. Appl Surf Sci 599, 153959 (2022).