A joint project of the Graduate School, Peabody College, and the Jean & Alexander Heard Library

Title page for ETD etd-04152011-161800


Type of Document Dissertation
Author Ferrara, Davon Wayne
Author's Email Address davon.ferrara@vanderbilt.edu
URN etd-04152011-161800
Title Plasmonic Interactions in Gold::Vanadium Dioxide Hybrid Nanostructures
Degree PhD
Department Physics
Advisory Committee
Advisor Name Title
Richard F. Haglund, Jr. Committee Chair
Anthony B. Kaye Committee Member
David E. Cliffel Committee Member
Leonard C. Feldman Committee Member
Sharon M. Weiss Committee Member
Thomas J. Weiler Committee Member
Keywords
  • phase transition
  • thermochromic
  • photochromic
  • laser
  • vanadium dioxide
  • plasmon
  • nanostructure
  • nanoparticle
  • nanocomposite
Date of Defense 2011-01-18
Availability unrestricted
Abstract
Hybrid nanocomposites consisting of arrays of gold (Au) nanoparticles (NPs) and vanadium dioxide (VO2) were fabricated on indium-tin-oxide coated glass substrates. The Au NPs, with radii from 100 to 180 nm and 20 nm in thickness, were created by electron beam lithography; subsequently, a VO2 thin film was deposited over the arrays by pulsed laser deposition. The localized surface plasmon resonances in the nanocomposite occur at visible to near-infrared (VS-NIR) wavelengths. At VS-NIR wavelengths, these Au::VO2 nanocomposites present a unique opportunity to study the interactions between the fundamental free-electron excitation of a metal, the plasmon, and the strongly-correlated electronic excitations that give rise to the VO2 semiconductor-to-metal phase transition (SMT). In particular, for Au NP arrays and VO2 thin films at wavelengths between 600 and 1200 nm, the electromagnetic coupling between the Au plasmon and the VO2 interband transitions crucially determine the optical characteristics of Au::VO2 structures. For arrays of single NPs, coupling between the plasmon and the VO2 interband transitions allows the NPs to serve as nanoantennas for probing the SMT, leading to a 30% reduction in plasmon dephasing time as the split 3d|| and 3dπ bands reduce in energy to form the metallic VO2 conduction band. By studying the interparticle interactions within pairs of interacting NPs, or nanodimers (NDs) embedded in VO2, we show that plasmon coupling to the vox interband transitions leads to a reduction in coupling strength over NDs in air. Finally, by using a 1550 nm CW laser and transient absorption spectrometry, the presence of Au NPs in a VO2 film is shown to enhance the photochromic response of the film to low-intensity irradiation by reducing the critical intensity necessary to induce the phase transition with a 785 nm CW laser. This enhancement results from an increased in absorption within the film due to the Au plasmon.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  DWFdissertationfinal.pdf 17.85 Mb 01:22:37 00:42:29 00:37:10 00:18:35 00:01:35

Browse All Available ETDs by ( Author | Department )

If you have more questions or technical problems, please Contact LITS.