The photophysical properties of a series of Zn (II) porphyrins adsorbed onto a
semiconductor were investigated using steady-state absorbance and emission
measurements. The ability of the porphyrins to undergo triplet-triplet annihilation (TTA), a photophysical process through which photons in the red and near-infrared (NIR) regions of the optical spectrum can be converted into higher energy photons (upconversion), was explored. Aggregation capabilities were determined to verify possibility of these molecules to undergo triplet-triplet annihilation (TTA). TTA has significant potential for increasing the efficiency of dye-sensitized solar cells (DSSCs) by
upconverting photons in the energy rich NIR region of the solar spectrum. A key
requirement for efficient TTA is aggregation of the sensitizer dye, and in this thesis, we have examined the aggregation of porphyrins in TiO2-based sol-gel films. Solution phase absorption and emission studies were conducted using zinc (II) tetraphenylporphyrin and
three of its functionalized derivatives, tetra(4-aminophenyl)porphyrin Zn(II), tetra(4-carboxyphenyl)porphyrin Zn(II), and tetra(4-sulfonatophenyl)porphyrin Zn(II), to
evaluate their potential as DSSC sensitizers on TiO2 thin films. Mesoporous TiO2 thin films were synthesized, using a polymer-templating sol-gel route, and characterized with
tunneling electron microscopy (TEM), atomic force microscopy (AFM), and UV-Vis absorbance measurements. Spectroscopy measurements were also carried out on porphyrin-sensitized TiO2 thin films and compared to solution-based results. A simple DSSC was constructed and used to further explore the application of zinc (II) porphyrin sensitizers in photovoltaic applications.
| Identifer | oai:union.ndltd.org:USASK/oai:ecommons.usask.ca:10388/ETD-2013-10-1028 |
| Date | 2013 October 1900 |
| Contributors | Paige, Matthew F. |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text, thesis |
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