FABRICATION AND CHARACTERIZATION OF PEROVSKITE STRUCTURES FOR SOLAR CELL APPLICATIONS

Solution-processing organic–inorganic hybrid perovskites have emerged as new generation and promising light-harvesting materials for photovoltaic technology and photonic applications such as solar cells, light emitting diodes and laser. The aim of this thesis is to boost the power conversion efficiency of planer perovskite solar cell by either using perovskite structure layer, or by doping perovskite thin film with metal ion to enhance the morphological, structure and optical properties of the perovskite thin film. The first proposed perovskite layer is based on CH₃NH₃PbBr₃ and was fabricated using one step self-assembly method. The method is appropriate to produce CH₃NH₃PbBr₃ microstructures in form of micro-wires, microplates and micro-cubes. The microstructures exhibit a cubic phase structure. The growth starts from the periphery and propagate to the center, giving forms of hollow cubes when the growth is not finished, and each cube is the superposition of several perovskite layers. The optical properties show an absorption peak at 523 nm and emission peak at 537 nm. On the other hand, the second layer is based on CH₃NH₃PbI₃ thin film doped with the monovalent metal ions Cu⁺ and Ag⁺. The thin films were fabricated using one-step solution process. The results indicate that doping CH₃NH₃PbI₃ thin film with small amount of Cu⁺ and Ag⁺ ions have modified the morphology and structure of the perovskite layer by enhancing the surface coverage and the perovskite conversion process. Besides, the optical properties show an improvement in the absorption and PL intensities. Based on these results, the perovskite solar cells were synthesized based on CH₃NH₃PbI₃ thin film doped with different concentrations of Cu⁺ ion. The consequences of altering the concentration of the Cu⁺ ion on the performance of the perovskite solar cell, were investigated. It was found that doping perovskite solar cell with small amount of Cu⁺ ion increased the power conversion efficiency of the solar cell from about 16.3% to 18.2%. While, the excessed amount of Cu⁺ ion led to a decrease in the power conversion efficiency of the perovskite solar cell to 4.4%