Given the inevitable depletion of non-renewable energy sources, photovoltaics is becoming increasingly interesting because it can convert sunlight directly into electrical energy and the energy production is environmentally friendly. Research on solar cells is multiplying in response to mass demand, leading to the development of third-generation cells. These include dye-sensitized solar cells (DSSCs). Since they are easy to manufacture with affordable components, they are becoming competitive to conventional silicon cells.
In my master's thesis, I focused on optimizing the working electrode with the aim of improving the functionality of DSSC cells. TiO2 microparticles were prepared by hydrothermal synthesis with different concentrations of added NaOH and then used to prepare a suitable paste for DSSC cells. I attempted to obtain the most effective TiO2 paste by varying the amount of dry components added, different combinations of solvents, and the addition of a surfactant. I used scanning electron microscopy to analyze the surface of the deposits and determined their thickness by recording cross sections. I measured the current-voltage characteristics of DSSC cells composed of the prepared TiO2 pastes and ruthenium dye using a solar simulator. I was mainly interested in the efficiency. At the same time, I also investigated the influence on successful energy conversion in DSSC cells by using different electrolytes and dyes, extracted from invasive plants.
The solar cell made with optimized TiO2 paste and ruthenium dye had the highest efficiency of 2.72%. This is a good approximation to a cell made with commercial TiO2 paste, whose efficiency was 2.80%. Combining dyes extracted from invasive plants with the most effective TiO2 paste, I made DSSC cells and evaluated their efficiency. Canadian goldenrod extract proved to be the most promising dye with an efficiency of 0.30%. The TiO2 paste prepared from synthesized particles also proved to be better at binding organic dyes.
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