Fundamentals of Film Growth by Glancing Angle Deposition for Inorganic and Inorganic/Liquid Crystal Hybrid Optical Systems

• Author / Creator

  Wakefield, Nicholas George

• This thesis investigates two facets of thin film growth via glancing angle deposition. The first half of the work focuses on the fundamentals of film growth with a focus on uniformity and optical design. This portion of the thesis addresses important engineering questions that are relevant to future commercialization of this technology, by investigating issues of scalability and repeatability, which are crucial for large scale manufacturing. This research is also directly applicable to laboratory research as it allows for combinatorial approaches to experimental design, and addresses experimental uncertainty in device performance. This work underscores the importance of film density and column tilt, and the material constants that quantify these parameters. This work illustrates how knowledge of these constants is sufficient to predict a wide variety of important film properties, including thickness, density and column tilt non-uniformities, and can be used to predict and design the anisotropic optical properties of columnar thin films. This design flexibility is illustrated experimentally in the fabrication of a novel, single material, thin film, normal-incidence, reflective linear polarizer. The second half of the thesis investigates the interaction between liquid crystalline molecules and nanoporous metal oxide films. It builds upon prior work by a number of researchers, and contributes a two-dimensional finite element model based on an elastic model of nematic liquid crystals in order to explain molecular alignment in these systems. The model indicates how film column tilt, film density and columnar aspect ratio contribute to molecular alignment, and suggests methods by which to achieve the desired film alignment. Experimentally, a number of reactive and non-reactive nematic liquid crystals are studied in silica thin films, with both hydrophilic and hydrophobic surface chemistries to examine real-world behaviour of a variety of systems. Finally, a system of fluorescent, reactive liquid crystals embedded in silica thin films placed on top of a transparent substrate is investigated for use as a luminescent solar concentrator, and is found to significantly enhance device performance.

• Subjects / Keywords

  • Nanotechnology
  • Uniformity
  • Glancing angle deposition
  • Metal oxides
  • Liquid crystal
  • Photonics

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R39H3Z

• 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.