ELECTROCHROMISM FOR LINEAR AND NONLINEAR NANOPLASMONIC AND DIELECTRIC NANOPHOTONIC DEVICES

• Author / Creator

  Hopmann, Eric

• The electrochromic (EC) effect has attracted constant research efforts since it was first described in the early 19th century. Conventionally, EC oxides (e.g., WO3, MoO3, V2O5, and NiO) are employed to modulate light transmittance in smart windows, which allow for up to 80% optical transmission modulation in several seconds. Recently, research in EC materials, in particular the optical properties of EC oxides, has led to novel functionalities transcending beyond their typical applications in smart windows. In a typical EC device light transmittance control is realized upon reversible ion intercalation, wherein resulting in modifying the real and imaginary parts of the refractive index. Dynamically altering the dielectric properties of an EC material gives direct control over the properties of nanophotonic devices. Furthermore, merging nanoplasmonics and nanophotonics with EC materials provides an additional degree of freedom and a new avenue to active control. Such an intriguing platform offers novel functionalities, such as dynamic high optical transmission modulation, structural color generation, and metasurface tunability at a low power consumption.
  This thesis investigates the possibilities of integrating electrochromic WO3 into nanophotonic and nanoplasmonic devices. First, long lifetime ionic conductors are evaluated for use in EC devices. Common ion conductors are liquids or polymers, as well as amorphous crystals, which contain ionic species such as H+ or Li+. Here, a polymeric poly acrylamide ion conductor is modified via simple chemical methods to increase its lifetime. Further, solid-state LiNbO3 processing for ionic conduction is investigated and tailored as potential solid-state ion source in nanofabricated devices. Second, these ion conductors are integrated in plasmonic, electrochromic (i.e., plasmochromic) color and optical transmission modulation devices, for full color plasmonic display applications and ultra-high optical transmission modulation. Last, WO3 is utilized in combination with a plasma-enhanced chemical vapor deposition (PECVD) Silicon Nitride waveguide platform to create novel functionalities, such as ultra-high transmission modulation sensor applications and dynamic phase tuning. Through the EC modulation layer, we create a novel nonlinear photonic structure with the ability to dynamically and reversibly tune the second harmonic wavelength generated in a SiNx waveguide.

• Subjects / Keywords

  • Electrochromism
  • Plasmonics
  • Nanophotonics
  • Waveguides
  • WO3
  • Smart Windows

• Graduation date

  Spring 2023

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/r3-1aqb-vb57

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.