Nanotechnology for solar module applications: zinc oxide nanostructures and anti-reflective coating modeling, deposition, analysis, and model fitting

Type
Thesis
Year of Publication
2014
Authors
Katherine M. Han
Volume
Ph.D.
Date Published
Jan. 1, 2014
Publisher
Oregon State University
Abstract

To become a competitor for fossil fuels such as coal, solar installations will need to be produced and installed at a price equal to or below grid parity. This price can be approached by either reducing the overall system cost or increasing system efficiency. The focus of this paper is on increasing both cell and module efficiency through application of nanotechnology and by numeral modeling. The first portion of this dissertation will focus on the production and characterization of zinc oxide urchin-like nanostructures. These nanostructures have a very high surface area to volume ratio. Such nanostructures could be appropriate for dye sensitized solar cells, an emergent PV technology. The second portion focuses on improving a solar module’s anti-reflective properties. In a traditional glass-encapsulated solar module at least 4% of the incoming light is lost to reflections off of the first optical interface alone. This in turn lower system efficiency and increases the levelized cost of energy. The power loss can be reduced greatly by thin film or gradient index anti-reflective coatings. An in-depth review of the current options for mathematical modeling of the optics of anti-reflective coatings is presented. The following chapter describes a numerical approach to anti-reflective interface design and a comparison between the finite-difference time-domain and the transfer matrix method of optical modeling. The last chapter describes several approaches to applying anti-reflective coatings to solar module lamination materials, including glass and a flexible substrate, fluorinated ethylene polymer. Scale up deposition of the anti-reflective coating on the flexible substrate is discussed.