Study On The Growth Kinetics Of Perovskite Films And The Performance Of Solar Cells

Organic-inorganic hybrid perovskite has drawn a lot of attention because of its high efficiency,the power-conversion efficiency(PCE)in small area devices had been increased to 25.2%,The crystallization ability and film formation of perovskite have a decisive influence on device performance and large-area fabrication.Therefore,it is particularly important to explore the controlling of perovskite film formation,further reduce the density of defect states,and understand the dynamic process of film formation.In view of this problem,this thesis starts with additives,and firstly introduces polyvinylpyrrolidone as an additive.On the one hand,the additives existing in the grain boundary reduce a large number of dangling bonds and play a role of defects passivation.On the other hand,we also studied the dynamic effects of the additives on the perovskite film formation.It is pointed out that the coordination of carbonyl and lead ions delays the phase transition process of perovskite,slows down the crystallization rate,and reduces internal defects.Finally,V_ocof 1.18V and efficiency of 19.8%were obtained,which further verified the defects reduction.We further studied the effect of the humidity stability of perovskite based on another additive,t-butyl acrylate(t BA).Through experiments,the humidity instability of perovskite is mainly due to the reaction of water molecules with dangling bonds existing at the grain boundaries,which induces phase transformation and finally decomposes.The t BA present at the grain boundaries has hydrophobic groups and can better blocks water from entering the grain boundaries,thereby improving the stability of the perovskite.Based on the dynamic analysis of the perovskite film-forming process with additives,a systematic process of large-scale film formation was also investigated.To sum up,this thesis has made in-depth exploration of the perovskite film formation process,and combined its dynamic process as a theoretical guide,further explores the large-area film formation process,improves the film formation quality,and has a certain reference significance.