Dye-sensitized Solar Cell Fabrication and light Trapping Modifications
Open Access
- Author:
- Friesen, Stuart Aaron
- Graduate Program:
- Chemistry
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- June 19, 2013
- Committee Members:
- Thomas E Mallouk, Thesis Advisor/Co-Advisor
Karl Todd Mueller, Thesis Advisor/Co-Advisor
Raymond Edward Schaak, Thesis Advisor/Co-Advisor - Keywords:
- robust fabrication process
inverse opal
stop band
Wood's anomalies - Abstract:
- The objective of this study was to design and build sensitized, porous semiconductor films composed of two optically different but mechanically fused planar layers, ordered 200 to 600nm and disordered 25nm semi-crystalline TiO2, in order to identify specific light wave scatterings, interferences and resonances within (i.e. Wood’s anomalies, cavity resonators, slow photon propagation, Anderson localizations, etc). Since robust, reliable construction methods for bilayer dye-sensitized solar cells (bi-DSSCs) fosters consistency in performance from cell to cell and a higher signal-to-noise ratio during photovoltaic action, which in turn aids in examining the single variable of interest, robust and experiment-tailored fabrication methods for producing bilayer dye-sensitized solar cell evolved into the main focus of this study. Three different bi-DSSC fabrication categories were pursued: 1) decal transfer of one layer onto the other; 2) build inverse opal (IO) directly on top of a mesoporous nanocrystalline TiO2 (meso ncTiO2) film; and, 3) build the meso ncTiO2 layer directly on top of an IO layer. Experimental observations of morphology, spectral responses and light-to-energy responses were made on all attempts to construct bi-DSSCs but none of the attempted methods proved successful for joining these two layers. An ncTiO2 particle infiltration into colloidal crystal template infiltration method is believed to be the most consistent and flexible IO layer fabrication method for bi-DSSCs. Isolation of the majority of pores within a meso nc-TiO2 film by way of atomic layer deposition (ALD) of Al2O3 onto the meso nc-TiO2 film’s outer surface followed by ion mill leveling is believed to be an effective method for bi-DSSC fabrication systems 1 and 2, above. It appears most useful for direct deposition of a colloidal crystal and subsequent infiltration with nc-TiO2 particles and/or a decal technique involving a milled IO layer attached to the Al2O3 protected meso nc-TiO2 using a newly developed TiO2 sol-gel that can form a meso film within submicron confined spaces and thus “glue” the two separately prepared films together. Due to a noticeable lack of easily accessible, easy-to-follow and complete guides to understanding and fabricating moderately efficient, ~6.5%, DSSCs, one was developed. It provides a quicker initiation into laboratory-grade DSSC building and testing without cumbersome steps such as dye purification, light scattering layer addition or ncTiO2 sol pretreatment of FTO or post treatment of the photoanode. Since DSSCs are relatively easy to fabricate, morphologies are easily altered and involve much less lab equipment than do other solar cells, providing this guide will be very useful for solar cell research in general at the undergraduate level as it facilitates less of an investment of time to get started.