Study On The Fluorescence Temperature Characteristics Of Cu²⁺ Doped CsPbI₃ Nanocrystal

CsPbI₃ nanocrystals are widely used material with strong luminescence efficiency in the infrared region.And it also has the most ideal suitable bandgap close to solar cells,often used for infrared detection and LED and other fields.The band gap of CsPbI₃ nanocrystals in inorganic perovskite is close to 1.3 me V.Although CsPbI₃ nanocrystals have great potential in fields such as solar cells,unfortunately,metal halide perovskite is very unstable at high temperatures and under the influence of water,air,and other factors.There are currently two main methods for improving the stability of perovskite materials.One method is to reduce surface defects of perovskite through ligand modification.However,this method will reduce the conductivity of the material and introduce a barrier for charge injection.Another method is ion doping,which improves the stability of perovskite by doping ions with different valence states.In this paper,the stability of nanocrystals was improved by ion doping,and the dependence of CsPbI₃ nanocrystals and CsPb_0.9Cu_0.1I₃ nanocrystals on fluorescence was analyzed by changing the temperature.The main content is as follows This article mainly studies the photoluminescence of CsPbI₃ and CsPb_0.9Cu_0.1I₃,as well as their thermal and time stability.It was found that the photoluminescence intensity and absorption coefficient of the doped material changed,and attempts were made to change the influencing parameters to measure the properties of the material.The main research includes:（1）By comparing doped and undoped materials,determine the changes in fluorescence temperature characteristics,thermal stability,and time stability of the two materials at room temperature and low temperature.Through fitting,the dependence of the luminous intensity,half height and full width,and the luminous peak position on temperature is obtained,and the reason for the peak position shift is analyzed,as well as the lattice constant of the material is calculated.The reason for the different stability of doped materials and undoped materials at low temperatures is found.（2）By changing the time and measuring the time stability of the two materials,it was found that the doped material still maintained a high luminescence efficiency after 14 days,while the undoped material had a significant decrease in luminescence efficiency after 7 days.Subsequently,changes in peak position,full width at half height,and other factors were measured and analyzed,and the reasons for these changes were described,Theoretical analysis of different experimental results for two materials.The conclusion is drawn that Cu²⁺doping effectively improves the time stability of the material.（3）By measuring its lifespan and using transient absorption methods,analyze the process of its lifespan decay,deeply analyze the internal operating laws of materials,as well as the process of energy transfer,and provide certain assistance for future research by others.