Preparation And Study Of Perovskite Solar Cells

With the further deterioration of the energy crisis and environmental pollution, developing new clean energy sources has become an important problem needed to be solved urgently. As an inexhaustible green energy, solar energy has become people’s first choice, where the solar cell is the best example of exploration of solar energy. The thin film solar cell based on organic inorganic perovskite grows rapidly within last five years, for it meets the requests of high efficiency and low production cost. Therefore, the fabrication techniques of perovskite solar cell and related researches on its material, physical and chemical properties have become important now.In this article, a series of characterization methods have been applied on two kinds of perovskite films, namely, CH3NH3PbI3 and CH3NH3PbI3-xClx. We measured the crystal structure of perovskite materials by means of XRD and SEM, also we measured Ultraviolet-Visible absorption and Photoluminescence spectroscopies and fluorescence lifetime to get its optical properties. From these experiments, we could find that the main results from CH3NH3PbI3 and CH3NH3PbI3-xClx are very similar, resulting from the very low content of element Cl in CH3NH3PbI3-xClx film. However, we found that the CH3NH3Pbl3 and CH3NH3PbI3-xClx films present different fluorescence lifetime, where the lifetime in CH3NH3PbI3-xClx is longer than it in CH3NH3Pbl3. This indicates that CH3NH3PbI3-xClx has less defect states. Then we studied the thermal stability of CH3NH3PbI3-xClx film, in which we conclude that the charge transfer between conductive substrate and perovskite film would reduce its the thermal stability. The corresponding degradation process of CH3NH3PbI3-xClx is then discussed. At last, we used two steps method to prepare perovskite solar cell based on high quality CH3NH3PbI3-xClx film, from which 10% efficiency is achieved from the best devices. Some useful parameters of perovskite solar cell were also achieved by means of formula fitting. Our work suggest that the systematically studies of relationship between the film’s morphology and photoelectric properties, as well as further understanding photophysics of photoexcitations will supply the foundation to further improve the efficiency of perovskite solar cell.