High-Quality Hybrid Perovskite Films Fabricated Via Intermixing Technology For Solar Cells

In the recent years,the perovskite solar cells(PSCs)have made rapid progress by virtue of their good light absorption and charge transfer rate.With the passage of time,the performance of PSCs is being improved by different process advancements and techniques.PSCs are composed of multi-layer thin films.The quality of perovskite optical absorption layer has a great influence on the device performance.Many studies have shown that the density of grain boundaries in the perovskite layers with large grains is significantly minimized.Large-grained perovskite films are beneficial for prolonging carrier diffusion length and reducing trap density and thus crystal growth dynamic of mix-perovskite for high-performance solar cells via intermixing technology.Traditional fabrication techniques of formamidinium(FA)based perovskite are insufficient to properly accommodate FA cation into the lattice,leaving behind masses of FA or lead halide content which can lead to a drop in performance of the device.A novel surface engineering technique of post-treating pure methylammonium(MA)based MAPbI3 films with FAI solution turned into a useful method.The MAI-based film with comparatively small grains size was fully transformed into a good quality mixed cation perovskite large grain size and highly crystalline orientation.FAI-post-treated MAPbI3 thin-film support uniform intermixing of anions and cations with a suitable lattice arrangement and produce mixed-cation based FAxMAi-xPbI3 PSCs with large grain size,compact and uniform morphology,and highly crystalline films.This post-treatment technique can transform the traditional fabrication process into a more advanced and scalable one,which can produce mixcation-based efficient,stable,and feasible PSCs.Intermixing engineering methods have been widely used to improve the morphology,crystallization,performance of the devices,and stability of perovskite solar cells.FABr is used to treat MAI-PbI2-DMSO film via a facile and reproducible process based on intermediate engineering techniques.The results show that the method can effectively produce large grain size and highly crystallization,consequently reducing the defect density of perovskite film.FABr treated film exhibits enhanced performance in comparison to control and traditional mixed cation and mixed halide film.The FABr effectively reduces the defects and increasing the carrier lifetime.The treated device’s performance is higher than without treated film and mixed cation mixed halide cells from the conventional way and also environmentally stable.FABr effectively reduces the film defects and improving the carrier lifetime.The performance of FABr treated film is higher than that of the untreated film,mixed cation,and mixed halide device from the conventional way and also environmentally stable.An effective method of intermediate engineering technology consists of dropping MACl solution on the pre-deposited films which construct the intermediate phase into the high-quality mixed perovskite film was introduced.It is worth noting that the immature MA-FAI-PbI2 intermediate can be treated with the optimized MACl solution to obtain high-quality mixed cation perovskite with large grain size and low trap density.Achieved high-quality mixed cation to obtain phase FAxMA1-x PbI3 perovskite thin film by using mixed cation and the surface morphology,crystallography,optical absorption and photo-luminescence properties of the film were enhanced.which resulted in high-performance perovskite solar cells.With achieved high-quality mixed cation to obtain phase resilient FAxMA1-xPbI3 perovskite film,the surface morphology,crystallographic properties,optical absorption,and photo-luminescence properties were enhanced,which resulted in high-performance perovskite solar cells.Introducing appropriate additives into the precursor solution can reduce film defects and greatly improving the morphology,crystallization,and efficiency of perovskite cells.A novel strategy is presented,utilizing a simple ethylammonium chloride(EACl)additive in combination to achieve high-quality MAPbI3 films.It is found that EACl could promote the perovskite grain growth by undergoing the intermediate phase formation and would evaporate from the perovskite after annealing.In addition,a gradient perovskite structure was obtained by this method,which greatly improved the efficiency and stability of perovskites.An effective power conversion efficiency of 20.03%is achieved under the optimal amount of EACl,and the resultant high-efficiency device.