In recent years, organic-inorganic hybrid perovskite solar cells have become a research hotspot in the photovoltaic field because of their excellent power conversion efficiency. However, this hybrid perovskite material's intrinsic instability and the harsh preparation environment limit its further commercial application. All-inorganic CsPbBr3 perovskite materials have attracted much attention because of their good stability, low cost and can be prepared in an atmospheric environment, showing great application potential. The controllable preparation and growth kinetics of CsPbBr3 materials need to be further studied, and the conversion efficiency of photovoltaic devices is still low. Considering the instability caused by traditional organic hole transport materials and their high preparation cost, this master dissertation focuses on systematically studies of CsPbBr3 all-inorganic perovskite cells without a hole transport layer as the research object. Growth kinetics materials of CsPbBr3 was directive by adding 2-phenylethylamine bromide to precursor solution. The main research contents and results are as follows:
Based on multi-step spin-coating preparation of CsPbBr3 perovskite films. Study on the perovskite cell preparation method and the critical process parameters include the spin-coating PbBr2, amount and number of spin-coating of CsBr, substrate preheating temperature, and the annealing temperature are optimized. The optimization tests show that the optimum spin-coating of CsBr is five times and the spin-coating PbBr2 in the atmospheric environment. The optimal preheating temperature of the substrate is 80℃, and the optimal annealing temperature is 100℃. The perovskite films prepared under this condition are compact with a continuous high phase purity and good crystallization performance.
The First adoption of PbBr2 in DMF and the addition of 2-phenylethylamine bromide (PEABr) solution to regulate the CsPbBr3 crystalline quality of the film. Effects of PEABr on the perovskite crystallization process and device performance are systematically investigated. The results show that the introduction of PEABr can effectively optimize CsPbBr3. The crystalline properties of the two-dimensional perovskite materials can improve the grain boundaries and improve their transport properties. The prepared perovskite solar cell with PEABr shows the highest power conversion efficiency of 8.25%, and it can maintain the efficiency of more than 90% when stored for 1500h under the condition of no encapsulation. Finally, stable, efficiency and low-cost all-inorganic CsPbBr3 solar cells without a hole layer are obtained.