Preparation Of Cesium Lead Halide Perovskite Nanoparticles Through Environmental Friendly Method And Their Optical Properties

All-inorganic perovskite has higher stability than organic-inorganic hybrid perovskite,with tunable photoluminescence color and high quantum yield.It can be used in lighting,nano-laser,solar cell and LED.In the recent years,it has attracted extensive attention and researchers have also developed a strong interest in it.However,there are two main methods for the synthesis of photoluminescent perovskite nanoparticles at present,one is the method of hot-inject.For this method,the complicated synthesis process needs to be carried out under the protection of inert gas,and the precursor should be pretreated before the reaction.The synthesis requires a high temperature and a certain amount of energy input,which is not suitable for large-scale production.Another is room temperature recrystallization method.Although this method can be reaction at room temperature in the atmospheric environment,the reaction process needs to use organic solvent such as toluene,DMF and DMSO,and these solvents have certain toxicity,and cause a harm to human health after volatilization.If industrial production produces a lot of waste liquid,it not only destroyed to the environment but also increased the burden of waste liquid treatment.The aim of this paper is to synthesize perovskite nanoparticles with high photoluminescence performance through environmentally friendly method.The formation,controllable preparation and photoluminescence performance of perovskite nanoparticles are studied systematically.The main research contents include:1.Pb₂?1,3,5-H₃BTC?₂?H₂O?₅ was prepared by using Pb?NO₃?₂ as lead source and 1,3,5-benzene tricarboxylic acid as ligand,and CsPbX₃/Pb₂?1,3,5-H₃BTC?₂?H₂O?₅?X=Cl,Br,I,Cl/Br and Br/I?composite photoluminescent materials were prepared by grinding from Pb₂?1,3,5-H₃BTC?₂?H₂O?₅.The prepared CsPbX₃/Pb₂?1,3,5-H₃BTC?₂?H₂O?₅ composite photoluminescence material has the characteristics of high photoluminescent intensity and full spectral adjustment of emission wavelength in the visible light range.The use of non-toxic organic solvents reduces the harm to the environment in the production process and is suitable for industrial large-scale production.A series of experiments were conducted to investigate the effect of the amount of reactant added in the synthesis process on its photoluminescence performance,and the optimal experimental conditions were obtained.Taking 1,3,5-H₃BTC as the ligand can limit the movement of Pb²⁺ions and prevent the formation of large particles in the grinding process,which simplifies the experimental process of preparing CsPbX₃nanoparticles by ordinary grinding.At the same time,the addition of PVP as the stabilizer increased the stability of the product.2.Using water and ethanol as solvent,PVP assisted to synthesize Cs₄PbX₆zero-dimensional perovskite nanoparticles with good photoluminescence performance.The prepared Cs₄PbX₆ has a high photoluminescence intensity and a narrow FWHM,and can adjust the photoluminescence emission wavelength within the visible light range by adjusting the halogen components.Cs₄PbX₆ nanoparticles have high photostability and thermal stability.Pb?NO₃?₂ was used as the lead source and CsBr as the cesium source,and the precursor could be dissolved in water to avoid the use of DMF.The addition of PVP could make Pb?NO₃?₂form a stable solution in ethanol.The effects of raw material addition,reaction solvent,PVP molecular weight and other experimental parameters on the photoluminescence performance of Cs₄PbBr₆ nanoparticles were systematically studied.The formation mechanism was demonstrated.The solubility of CsBr and Pb?NO₃?₂ in ethanol was much lower than that in water.Therefore,after being dissolved in water,adding anhydrous ethanol would crystallize.