Study On Photoelectric Properties Of The Electron Transfer Layer Based On Perovskite Solar Cells

In recent years, the development of perovskite solar cell is rapid. Compared with traditional dye-sensitised solar cells, its photoelectric conversion efficiency is much higher, with a wider space for further development. The CH3N3PbI3 films and the electron transport layer are the core parts of perovskite solar cell, they directly affect the performance of the whole battery devices. In this paper, the CH3NT3PbI3 films were prepared through the preparation technology, it mainly investigates the photoelectric conversion efficiency of TiO₂ nanoparticles films, ZnO nanorods film and graphene/TiO₂ nanorods composite film which were acted as the electron transport layer of the devices.TiO₂ nano-particles, ZnO nanorods and TiO₂ nanorods were prepared by the hydrothermal method. The microstructure of the powders were investigated by using XRD, TEM and SEM. The size distribution of the TiO₂ nano-particles by the hydrothermal reaction at 230? was uniform, and its particle size was about 20 nm. The length range of the spiauterite ZnO nanorods by the hydrothermal reaction at 180 was in the range of several hundred nanometers to a few microns, and its diameter was about 60 nm. The TiO₂ nanorods by the hydrothermal reaction at 180? grew well, with the length range of 200?300 nm, with a diameter of about 20 nm.TiO₂ nano-particles were used as the electron transport layer of devices. Through the optimization of the preparation technology of CH3NH3PbI3 films, it investigates the rotational speed of the PbI3 films, the time and the concentration of the PbI3 films immersed in CH3NH3I solution, the annealing temperature and time of the CH3NH3PI3 films. The photoelectric conversion efficiency of the perovskite solar cell was 7.83% under the AM-1.5 illumination of 100 mW/cm2. with the rotational speed of the PbI2 films of 3000 r/min, the immersed time of 20 s, the concentration of CH3NH3I solution of 0.01 g/mL, the annealing temperature and time of 70? and 25 min, respectively.ZnO nanorods film and graphene/TiO₂ nanorods composite film were used as the electron transport layer of the devices. The perovskite absorption layer was prepared and assembled into devices, it analyzes the absorption ability of the absorption layer, the photoelectric conversion efficiency and the stability of the battery device. The photoelectric conversion efficiency of the perovskite solar cell prepared with the graphene/TiO₂ nanorods composite film of graphene mass content of 3% was 7.94% under the AM-1.5 illumination of 100 mW/cm2. The photoelectric conversion efficiency of the devices decreased from 7.94% to 6.85% in 10 test days, with the loss rates of 13.7%. It indicated the photoelectric conversion efficiency and stability of the devices of graphene/TiO₂ nanorods composite film were higher.