Preparation And Ferroelectric Properties Investigation Of Perovskite CH₃NH₃PbI₃ Thin Films

In recent years,a organic-inorganic hybrid perovskite composite materials（for example,CH₃NH₃PbX₃,X = Cl,Br,I）become a hot topic.First of all,the perovskite compound oxide has a unique crystal structure that have flexible orthorhombic,tetragonal,cubic,monoclinic and other polymorphic phase transformation prototype system,and can be induced to undergo reversible phase transformation by a series of external stimuli such as temperature,pressure,magnetic field or electric field,which cause professional attention such as chemistry,physics and materials;Secondly,perovskite CH₃NH₃PbI₃ material have some characteristics,such as low cost,high carrier mobility,absorption coefficient and so on.However,the organic-inorganic hybrid perovskite material has many hole defects in the film formation,which limits its application in the fields of electroluminescence,lasers,and display.So the perovskite composites still need to be further explored.Recently,studies have shown that it can effectively reduce the hole defects with the decrease in the size of perovskite.Organic-inorganic hybrid perovskite have mainly large size in practical applications,so the film preparation process restricts its development.In this paper,we will mainly explore a new method of perovskite CH₃NH₃PbI₃ thin film preparation process,and explore whether it has ferroelectric properties.The main contents are as follows:（1）We explore a method of constructing polycrystalline perovskite thin films by low-temperature solid-phase auxiliary solution process----Thermosetting Interface Reaction.The perovskite thin films with the film thickness of about 300 nm and the grain size of the micron level were obtained at 100℃ by the experimental investigation.And provides a simple method to prepare perovskite thin films.（2）We explore a method of constructing polycrystalline perovskite thin films by thermal spraying.The method can be used to prepare the perovskite CH₃NH₃PbI₃ thin films easily and quickly.It is a new method for the preparation of perovskite thin films.（3）The ferroelectric properties of perovskite CH₃NH₃PbI₃ material were investigated.The ferroelectric properties of the perovskite CH₃NH₃PbI₃ were investigated by piezoelectric coefficient test,electric hysteresis loop test and scanning electron microscopy.