Tracking Energy Relaxation Within Plasmonic Metal Oxide Nanocrystals
Abstract
In this report, we have used transient absorption spectroscopy to examine how photoexcitation modifies the optical properties of two metal oxide systems, Sn-doped indium oxide (ITO) NCs and oxygen-vacancy doped tungsten oxide (WO3-x) NCs. Plasmonic excitation of either material generates hot electrons on a sub-picosecond timescale that later cool by releasing their energy to lattice phonons. Both of these processes alter the center frequency and line width of a NCs plasmon resonance, but the magnitude of these changes depend on the NCs size, crystallographic structure, and the spatial location of dopants within it. We have also investigated how bandgap photoexcitation can be used to manipulate the plasmon resonance ofWO3-x NCs. Adding additional charge carriers into the conduction band of these NCs induces a hypsochromic shift of their plasmon resonance that dissipates on picosecond timescales once the exciting field is removed, making these materials interesting candidates for fast photoswitches and photonic gates.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 2016
- Accession Number
- AD1036186
Entities
People
- Sean T Roberts
Organizations
- University of Texas at Austin