| In recent years,compared with other solar cells,due to the advantages of strong light absorption,high carrier mobility,and long carrier diffusion length,the emerging hybrid perovskite solar cells have achieved tremendous development in just a short time.In 10 years,its photoelectric conversion efficiency has rapidly increased from 3.8% to the current certification efficiency of 25.2%,which is regarded by authoritative scientific magazines as one of the new high-efficiency solar cells with the most potential for application development.The high-speed growth of perovskite solar cell efficiency is ultimately due to the continuous optimization of the structure of perovskite solar cell devices,as well as the high surface coverage of the film,low surface roughness and good grain quality.Based on the inverted planar heterojunction battery structure,this paper explored the effects of anti-solvent types,annealing temperature environment and composite solvent atmosphere on the quality of perovskite crystals,hoping to reduce the defects on the surface of the perovskite film and improve the quality of the film grains.To achieve the purpose of controlling and preparing high-performance perovskite solar cells.The main contents of this article are as follows:1.The type of antisolvent regulates the crystal form of perovskiteWhen extracting perovskite with an antisolvent,different antisolvent types(sec-butanol,chlorobenzene,isopropanol)are used to extract the solvent of the perovskite film to a certain extent,resulting in a flat and dense perovskite film However,when different antisolvent systems are used,the perovskite thin film crystals differ significantly and the flatness is also different.In view of this phenomenon,this paper systematically studies the effects of sec-butanol,chlorobenzene,and isopropanol as antisolvents on the morphology and photoelectric properties of perovskite films,and lays a foundation for the precise adjustment of perovskite morphology by optimizing antisolvents.2.The effect of annealing temperature distribution on the growth of perovskite crystalsAs we all know,in the process of nucleation of perovskite crystals,the humidity,temperature distribution and stability of the environment will significantly change the crystallization process,resulting in poor repeatability of the preparation of perovskite thin films,so it is stable,controllable,and thermally distributed.A uniform annealing atmosphere is crucial to the key step of perovskite annealing.This paper is the first to adopt a closed and well-heated iron box container as the annealing atmosphere environment,so that the perovskite grains grow under critical dissolution and recrystallization conditions,and a controlled annealing atmosphere environment can be formed to a certain extent to obtain optimized crystal quality Perovskite film.3.The effect of composite solvent atmosphere on the morphology of perovskite filmDuring the annealing process of perovskite thin film crystals,a suitable solvent atmosphere will form an atmospheric vapor at high temperature.The steam will continue to dissolve,diffuse and reorganize the crystal particles,which helps to grow more crystal size,high crystallinity,smooth and compact Perovskite film.However,the simple solvent atmosphere is also prone to form thin film defects at the grain boundaries and the thin film surface due to solubility,which in turn affects the charge movement and restricts the performance of the perovskite device.Therefore,it is necessary to systematically explore the controlled solvent atmosphere to ensure the quality of the perovskite film.In this paper,the effects of solvent atmosphere concentration,maintenance time length and time point on perovskite thin films are studied,as well as the mixed atmosphere of DMSO,DMF,CB,IPA and other solvents to investigate the effect of thin film photoelectric performance. |
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