CaltechTHESIS
  A Caltech Library Service

Resonant metallic nanostructures for active metamaterials and photovoltaics

Citation

Pryce, Imogen Mary (2011) Resonant metallic nanostructures for active metamaterials and photovoltaics. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:05282011-153554049

Abstract

Electromagnetic metamaterials are composites consisting of sub-wavelength structures designed to exhibit particular responses to an incident electromagnetic wave. In general, the properties of a metamaterial are fixed at the time of fabrication by the dimensions of each unit cell and the materials used. By incorporating dynamic components to the metamaterial system, a new type of tunable design can be accessed.

This thesis describes the design and development of resonant metallic nanostructures for use in active metamaterials. We begin by examining passive systems and introduce concepts that are critical for the design of more complex, tunable structures. We show how a simple metamaterial design, a plasmonic nanoparticle array, can be used to enhance the photocurrent of an ultrathin InGaN quantum well photovoltaic cell. We then explore how more complex resonator shapes can be coupled together in a single unit cell in order to access more complex resonant behavior.

In the second half of this thesis, we use several material systems as the basis for the design of active metamaterials. We demonstrate the first tunable metamaterial at optical frequencies using vanadium dioxide, a phase transition material. We exploit this material's transition from a semiconducting to a metallic state and show how a novel fabrication scheme can be used to achieve a frequency tunable resonant response. We then abandon traditional hard and brittle substrates and develop a lithographic transfer process for adhering metallic nanostructures to highly compliant polymeric substrates. Mechanical deformation is then used to distort the resonator shapes and achieve resonant tunability of a full linewidth. This system is exploited to demonstrate interesting resonant hybridization phenomena, such as Fano resonance modulation, and sets the stage for the more elusive goal of driving two resonant nanostructures into contact. Finally, we describe the use of compliant tunable metamaterials as both refractive index sensors and surface enhanced infrared absorption (SEIRA) substrates. The results highlight the promise of post-fabrication tunable compliant metamaterial sensors and the potential for integration with spectroscopic devices in remote sensing and microfluidic device applications.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:active metamaterials ; plasmonic sensor ; mechanical tunability ; metallic nanoparticles ; resonant structures
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemical Engineering
Minor Option:Applied Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Atwater, Harry Albert
Thesis Committee:
  • Atwater, Harry Albert (chair)
  • Haile, Sossina M.
  • Giapis, Konstantinos P.
  • Scherer, Axel
Defense Date:7 June 2011
Author Email:imogen.pryce (AT) gmail.com
Record Number:CaltechTHESIS:05282011-153554049
Persistent URL:http://resolver.caltech.edu/CaltechTHESIS:05282011-153554049
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6471
Collection:CaltechTHESIS
Deposited By: Imogen Pryce
Deposited On:01 Nov 2012 18:37
Last Modified:17 Jan 2013 17:16

Thesis Files

[img]
Preview
PDF (Thesis) - Final Version
See Usage Policy.

19Mb

Repository Staff Only: item control page