Study On The Influence Of Inorganic Perovskite Morphology Control On The Performance Of Solar Cells In Atmospheric Environment

In recent years,the research and application of new thin-film solar cells have been developed to a large extent,and new solutions have been proposed for the energy shortage and environmental pollution problems in today’s society.In 2009,perovskite solar cells（PSCs）were born and attracted the attention of researchers all over the world.The new type of organic-inorganic hybrid PSCs developed rapidly in the early stage.The current photoelectric conversion efficiency（PCE）has been able to reach the level of commercial solar cells,but to carry out commercial promotion,stability issues are the biggest challenge.Replacing the organic-inorganic hybrid perovskite with a stable inorganic perovskite is one of the effective methods to improve the stability of the device.The all-inorganic perovskite Cs Pb Br₃ has good moisture resistance,and can be prepared in an atmospheric environment,and has very good application prospects.However,the low PCE that has been reported so far is mainly due to the wide band gap（2.3 e V）of Cs Pb Br₃,which makes the light absorption range of the device narrow.In addition,the crystallinity and defects of the perovskite film will also cause relatively high PCE.Big impact.Based on this,this article starts from improving the photoelectric conversion efficiency of the all-inorganic Cs Pb Br₃ perovskite solar cell,optimizes the experimental plan,improves the film quality,and reduces the grain boundary defects.Based on the preparation process of traditional battery devices,the work focused on process optimization,interface engineering,solvent engineering and additive engineering,and discussed the optical properties of high-quality perovskite films.The main research work of the thesis is as follows:1.Interface modification and partial doping of quantum dots in all-inorganic Cs Pb Br₃ perovskite solar cells.By using synthetic graphene oxide quantum dots to modify the interface between the electron transport layer（ETL）and the perovskite light-absorbing layer（Per）,the energy level difference of different layers of the battery is adjusted,energy consumption is reduced,and electron transmission is more conducive;On the other hand,the partial doping of quantum dots also optimizes the perovskite film to a certain extent,so that the grain size after annealing becomes larger and the defects are reduced.The photoelectric conversion efficiency of perovskite solar cells modified based on quantum dots has increased from the initial 5.56%to 9.18%,and the fill factor of the battery devices has also increased from the initial 70.2%to 77.8%.2.The effect of different solvents on the conversion efficiency of Cs Pb Br₃.Seek greener solvents to replace toxic solvents to achieve a more environmentally friendly preparation environment.Cesium bromide has low solubility in methanol solvent,and methanol is a toxic solvent,but cesium bromide has high solubility in water,and water is a pure natural green solvent,which is not harmful to humans and the environment.We compared the three solvents Influence on the photoelectric performance of all-inorganic Cs Pb Br₃ perovskite solar cells.It is found that under water system conditions,the open circuit voltage of the device will be lower,but the fill factor（FF）and PCE will be significantly improved,and the stability of the device will be improved once,and it can be stored in the air for 30 days without significant degradation.3.The dye molecule N719 is used as an additive to optimize the crystal morphology of Cs Pb Br₃.N719 is one of the most effective conventional sensitizers for dye-sensitized solar cells.It has a wide absorption spectrum and fast electron transfer.It has a good match with perovskite and is a promising additive.In the experiment process,water was used as a solvent to dissolve Cs Br,and an appropriate amount of N719 powder was weighed and doped into the active layer of perovskite by solution spin coating.Characterization methods such as XRD and SEM proved that the crystal face size of the active layer was significantly increased,the defects were significantly reduced,and holes,etc.The phenomenon is well suppressed,so that the efficiency of the battery device measured in the air is once again increased to 10.1%,achieving a fill factor as high as 82.1%.