Structural Fabrication and Performance in Dye Sensitized and Perovskite Solar Cells

Conventional silicon based solar cells utilize electron/hole donor and acceptor materials to produce the photovoltaic effect, however difficult fabrication processes and depreciating photo-electric conversion efficiency at high temperatures are major obstacles in the current solar cell market. This study strives to develop new types of Dye Sensitized Solar Cells (DSSCs) and Perovskite Solar Cells by utilizing new materials, in an effort to improve photo-electric conversion efficiency and fabrication processes. DSSCs produce the photovoltaic effect by using photo-sensitized dye to free electron charge carriers. These free electrons dissociate through a layer of mesoporous TiO₂ towards a transparent electrode, and the dye electrons are regenerated by a redox reaction with a liquid iodine based electrolyte that is catalyzed at the counter electrode. DSSCs are highly versatile in terms of components and structure; they can be produced in planar, flexible, and fiber based structures. Perovskite solar cells utilize CH₃NH₃PbX (methyl ammonium lead halide crystals) for light absorption. When struck with photons, CH₃NH₃PbX produces electron/hole pairs that flow through the solar cell with the use of electron and hole transfer layers. The large band gap and high electron diffusion length of the CH₃NH₃PbX enables high open circuit voltage, greater electron mobility, and high photo-electric conversion efficiency. In this study, five different structures of solar cells were developed: two different types of planar DSSCs that used different catalysts, flexible DSSCs, fiber DSSCs, and planar Perovskite Solar Cells. The Perovskite Solar Cells provided the highest individual efficiency at 9.14%, while the planar DSSCs catalyzed with platinum had the highest mean efficiency of approximately 4%. The perovskite solar cells had the easiest fabrication process as they were developed using temperatures under 200°C. The flexible and fiber DSSCs provided the greatest potential applicability as they have the potential to be incorporated in plastic products, smartphones, and textile industries. The relatively high photo-electric conversion efficiency along with the application potential of the DSSCs and Perovskite Solar Cells illustrates the rising effectiveness of new types of solar cells. Further developments of these solar cells can lead to an economically beneficial large market solar industry, a significant drop in the carbon footprint caused by polluting fossil fuels, as well as a new method for peripheral countries to harvest energy.