Pavle Radovanovic
University of Waterloo, Canada
Title: Tuning plasmon resonance of In2O3 nanocrystals throughout mid-infrared: Dopant, phase, and electronic structure dependence
Biography
Biography: Pavle Radovanovic
Abstract
Synthesis, properties, and applications of gold and silver nanostructures with tunable localized surface plasmon resonances (LSPRs) have been a subject of intense investigation over the past decade. The focus on these noble metal plasmonic nanomaterials stems from their facile synthesis, stability to oxidation, and the visible-range LSPR transitions. However, among other drawbacks, these nanostructures are also costly for large-scale applications and exhibit high optical losses. Consequently, doped transparent metal oxide nanocrystals have emerged as a new class of unconventional plasmonic materials. In this talk, author will present the results of our recent work on colloidal indium oxide-based plasmonic nanocrystals. Using size-structure correlation, indium tin oxide (ITO) nanocrystals were prepared in the stable bixbyite (bcc-ITO) and metastable corundum (rh-ITO) phase, revealing a dramatic difference in their optical and electrical properties. Unlike rh-ITO, bcc-ITO nanocrystals exhibit a strong LSPR absorption in the near-infrared region due to the presence of free electrons, enabled by the low activation energy donor states. Author will also discuss colloidal synthesis and spectroscopic properties of two new plasmonic nano crystal systems based on In2O3, antimony and titanium-doped In2O3, and comparative investigation of their electronic structure using combined Drude-Lorentz model and density functional theory. Fundamental understanding of the electronic structure and phase-dependent plasmonic properties allowed us to design and prepare plasmonic In2O3-based nanocrystals tunable throughout the entire mid-infrared region. Application of these colloidal mid-IR plasmonic nanocrystals will also be discussed.