Date of Graduation

12-2019

Document Type

Thesis

Degree Name

Master of Science in Microelectronics-Photonics (MS)

Degree Level

Graduate

Department

Graduate School

Advisor

D. Keith Roper

Committee Member

Lauren Greenlee

Second Committee Member

Ryan Tian

Third Committee Member

Rick Wise

Keywords

Discrete Dipole Approximation, Nanoantennae, Nanocrystals, Nanostructure, Noble Metal, Semiconductor

Abstract

Noble metal nanoparticles and two-dimensional (2D) transition metal dichalcogenide (TMD) crystals offer unique optical and electronic properties that include strong exciton binding, spin-orbital coupling, and localized surface plasmon resonance. Controlling these properties at high spatiotemporal resolution can support emerging optoelectronic coupling and enhanced optical features. Excitation dynamics of these optical properties on physicochemically bonded mono- and few-layer TMD crystals with metal nanocrystals and two overlapping spherical metal nanocrystals were examined by concurrently (i) DDA simulations and (ii) far-field optical transmission UV-vis spectroscopic measurements. Initially, a novel and scalable method to unsettle van der Waals bonds in bulk TMDs to prepare mono- and few-layer crystals was performed. Examination of the solution-based and electrochemical deposition of metal nanocrystals on 2D TMD crystals, comparing their optical, electronic, and optoelectronic characteristics was accomplished via characterization methods. Subsequently, DDA simulations for noble metal - semiconductor nanocrystal and noble metal - noble metal nanocrystal heterostructures analyzed the effects of metal type, geometry, and orientation for the predefined nanoantennae parameters. Results from these computational and experimental optical spectra demonstrate promising percent error difference, in which distinguished quantitative effects of 2D TMDs crystals - metal nanocrystals and metal nanocrystals - metal nanocrystals facilitated optoelectronic activity in the UV-Vis-NIR region. New experimental and theoretical insights into energy conversion interactions between coupled plasmonic and excitonic materials spanning the optical regimes were established towards their applications in optoelectronic and biological engineering platforms.

Share

COinS