Date of Award
Master of Science
AN ABSTRACT OF THE THESIS OF MATTHEW BEHNKE, for the Master of Science degree in Mechanical Engineering, presented on November 3rd, 2015, at Southern Illinois University Carbondale TITLE: INVESTIGATION OF YTTRIUM TITANATE IN A LEAD IODIDE PEROVSKITE SENSITIZED SOLAR CELL TO ENHANCE EFFICIENCY MAJOR PROFESSOR: Dr. Kanchan Mondal This research is aimed to evaluate the effects of a pyrochlore to enhance the efficiency of a solid state organic inorganic halide-sensitized solar cell. The objectives of this study are to synthesize, assemble, test, and evaluate a pyrochlore that will lower the band gap of TiO2 and increase conversion efficiency in solid state organic-inorganic halide sensitized solar cells. The cells that were constructed and evaluated were made up of titanium oxide (TiO2) or yttrium titanate (Y2Ti2O7), a perovskite organic lead iodide (CH3NH3PbI3) as the polymer, a hole transport membrane (HTM) made of 1,3,5-Tris(diphenylamino) benzene, a layer of carbon black, and Indium Tin Oxide (ITO) coated glass. The cells were characterized and tested under a 658 nm wavelength light with a power density of 65 mW/cm2 , while the individual substances were examined under a scanning electron microscope and transmission electron microscopes and x-ray diffraction analyses were conducted to determine the structural make up of the individual materials. From the obtained data cell conversion efficiencies and fill factors were calculated. It was found that the Y2Ti2O7 nanofiber based cells exhibited the highest fill factor of 0.57 compared to 0.20 -0.29 obtained during the experiments with TiO2 based cells. The cell efficiencies of the Y2Ti2O7 were however low probably due to a significant portion of amorphous material in the photoactive layer of the cell.
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