Nonlinear photonics properties of NbS2 and Hybrid NbS2 2D LTMDs- THz spectroscopy and fundamental studies on LTMDs behavior in liquid crystal-cell geometry
Abstract
Layered Transition Metal Dichalcogenides (LTMDs) are bidimensional nanostructured materials beyond graphene, being available in semiconducting, semi-metallic or metallic structures (1), which is advantageous over graphene for applications in optoelectronics and nonlinear opticsbased devices (2). This proposal represents an acceleration grant which will take the information learned on the nonlinear optical (NLO) properties of several LTMDs materials in liquid suspension and working in the visible-near infrared spectral regime, extending the studies to the THz regime. Furthermore, we shall assess their capability in liquid-crystal cell geometry for potential switching applications. The work is being carried out under the current grant (Nonlinear photonics properties of NbS2 and Hybrid NbS2 2D LTMDs, FA9550-20-1-0381) and the acceleration grant will allow the Navy and AF research labs to transition the knowledge about these materials to a TRL 2-3, expanding the spectral studies to the THz regime. The NLO properties of the materials under study will be at a stage where their basic properties and fundamental limits for specific applications would be understood at the end of the current effort and would need an additional 2-3 years of further study-development before they are at the stage of TRL 4-5. One of the new frontiers in LTMDs research is in the THz regime, a region lying between the spectral infrared to near-infrared-visible and microwave regime. We shall start a new line of studies in the THz regime with the LTMDs already available, including the hybrids LTMDs. The THz system will be based on a 800nm, 100fs mode-locked Ti-sapphire as the optical source to generate THz radiation. During the single year acceleration grant, we shall carry out the spectroscopic and time-resolved characterization of the available LTMDs (pristine and hybrid), with emphasis on NbS2, although other materials will also be characterized. NbS2 is of special interest because it is a metal, which is expected to exhibit complementary physics to previously reported semi conductive MoS2 in the THz regime. Furthermore, the hybrid-NbS2 is isoelectric with MoS2, and exhibits a semi conductive optical response. The resulting fundamental experimental knowledge of these LTMDs will establish a crucial foundation for future theory and modeling development. The overall goal will be the characterization of basic features of the LTMDs as sources and detectors for THz radiation. A second topic of interest includes fundamental studies on LTMDs behavior in liquid crystal-cell geometry. Based on the earlier studies provided by NRL-AFRL (3 and refs therein) and our joint work (4), we shall extend the studies to look into the fundamental limits of switching behavior in gold nanorods (as a benchmark) and LTMDs as novel nanomaterial, and then design experimental tests for switching and transmissivity behavior based on the theoretical results. Experimentally, in "both cases (gold nanorods and LTMDs) we shall try to optimize the solvent, electric field and other relevant factors. The novel redox exfoliation method for LTMDs addresses many of these challenges by providing anhydrous, additive-free, stable dispersions at a wide range of concentrations. Therefore, these aspects will be considered in the present studies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 22, 2024
- Source ID
- FA95502310023
Entities
People
- Anderson Gomes
Organizations
- Air Force Office of Scientific Research
- United States Air Force