Discipline: Technology and Engineering
Subcategory: Materials Science
Jennifer Delgado - University of Chicago
Co-Author(s): Lisa C. Klein, Ph.D. Rutgers University, New Brunswick, NJ
A dye-sensitized solar cell (DSSC) is a solar cell that runs on a photoelectrical system. Its four main components are titanium dioxide paste, dye, electrolyte, and two conductive fluorine doped tin oxide (FTO) glasses. Benefits of DSSCs include low cost and low toxicity of its components. This is particularly appealing because economic advantages of renewable energy over fossil fuels would facilitate the shift towards renewable energy. The goal of this research is to improve the longevity and efficiency of DSSCs by exploring the electrolyte component of the solar cell. The electrolyte is responsible for the regeneration of the oxidized dye, which allows for the electrons to keep traveling within the cell to create an electric current. The electrolyte influences the efficiency and stability of the solar cell, therefore finding ways to improve electrolytes directly improves the efficiency and longevity of the solar cell. While there are a variety of different types of electrolytes, this research focuses on organic solvents, which fall under the category of liquid electrolytes. High ionic conductivity and low viscosity are desirable qualities in an electrolyte, but are not usually found in a single organic solvent. This research consisted of mixing existing organic solvents in five different ratios in order to test whether these mixtures work better than electrolytes made out of a single organic solvent. The two organic solvents used were propylene carbonate (P.C) and ethylene glycol (E.G). The voltages of these DSSCs were measured over time under different light sources, including sunlight, light from an incandescent lamp, and fluorescent light. Results showed that over time, under any light source, the mixtures of either 50% E.G 50% P.C or 75% P.C 25% E.G always had higher voltages than 100% E.G or 100% P.C. This showed that mixing organic solvents enhances the electrolyte and improves the performance of the DSSC. The reason as to why this happens is unknown, but this prompts the continuation of this research to study the properties within the individual electrolyte mixtures. This would be done to try to understand why mixing organic solvents in certain ratios creates a superior electrolyte. If the reason for this is found, it could facilitate the creation of better electrolytes for DSSCs, which would then directly improve DSSCs. A second part of this research focused on creating a sealant to test how it affected the efficiency and longevity of the cell. The goal was to help prevent the leakage and evaporation of electrolytes. The sealant was prepared by mixing Duramax and kaolin clay. Results showed that the sealant decreased the evaporation of electrolyte. Under direct sunlight, the voltage of the sealed DSSC decreased 1.4% while the unsealed DSSC decreased 14% over the span of three days.
Not SubmittedFunder Acknowledgement(s): NSF (National Science Foundation)
Faculty Advisor: Lisa C. Klein, licklein@soe.rutgers.edu
Role: I was responsible for building the dye-sensitized solar cells that were tested for this research. This included creating the dye, electrolytes, and titanium dioxide paste and assembling the components to make the dye-sensitized solar cells. It was also my responsibility to test the solar cells under the different lighting conditions and collect the data over time. For the second part of the research, I was responsible for making and testing different sealants for the solar cells.