Research Progress on Preparation Technology and Stability of Perovskite Solar Cells

Due to the simple preparation process, low cost and excellent photoelectric conversion efficiency, organic-inorganic hybrid perovskite solar cell has become a research hotspot in the field of photovoltaic technology. The perovskite optical absorption material has the advantages of high extinction coefficient, high carrier mobility, long carrier diffusion distance, long carrier lifetime, adjustable band gap, and a variety of preparation methods. In recent years, the efficiency of perovskite solar cells increased from the initial 3.8% in 2009 to the current 22.1%. In order to obtain long-term stable and high efficient perovskite solar cell at present, main research ideas have the following aspects including new structure design for solar cell, morphology design for functional layer, interface modification between each functional layer, selection of hole transport material and selection of counter electrode. Based on the review of the research progress of the perovskite solar cell, we first introduced the structure and working principle of the perovskite solar cell in this paper. Besides, the preparation process and various modification methods of electron transport layer were emphatically summarized. The electron transport layer plays a role in the transport of electrons and blocking holes in the structure of the perovskite solar cell. The energy level of electron transport layer can be controlled by doping technology to obtain better photoelectric conversion efficiency. The introduction of modification material on the electron transport layer can improve the morphology of the perovskite optical absorption layer, which can enhance the transmission and collection efficiency of the charge to improve the photoelectric conversion efficiency of the device. Afterwards, the synthesis optimization methods of the perovskite films were also discussed. The morphology and crystallinity of perovskite films can directly affect the optical trapping efficiency and short circuit current density. Therefore, high quality perovskite thin films were obtained by means of synthesis optimization, solvent engineering and annealing engineering. Moreover, we analyzed the reasons for the poor stability of perovskite solar cells, and then put forward the strategy to improve the stability of the solar cell. Finally, the commercial prospects of perovskite solar cells are forecasted.