Synthesis Of CsPbX₃ Nanocrystals By Thermal Injection

All inorganic perovskite type CsPbX₃ nanocrystalline because of its high absorption coefficient,high luminous efficiency,narrow emission spectrum,light color easy to adjust the excellent performance,such as in the fields such as photoelectric display,LED and solar cells has a great application potential,thus luminescence materials research focus in the last two years,but because of the heavy metals lead against environmental and other negative factors limit its wide application.Starting from the preparation of high-quality CsPbX₃ perovskite nanocrystites,this paper explored the influences of various reaction conditions on the properties of the products,optimized the preparation process,and reduced the lead content of the products by using two doping methods to improve the luminescence properties of the products.Through the hot shots is the preparation of pure phase CsPbBr₃nanocrystalline,explore gas environment,reaction time,the effect of surfactants on nanocrystalline synthesis process,research Br^-/Cs⁺amount of substance ratio on the nanocrystalline optical performance,by XRD,TEM,absorption spectrum and fluorescence spectrum test means,the crystal structure of the product,microstructure and optical properties were characterized,eventually won the good monochromaticity,high fluorescence intensity,the product with high luminous efficiency,fluorspar CsPbBr₃ characteristic peaks in spectra at 514nm,half peak width for 37nm,grain size is about 12nm.In the preparation process of perovskite nanocrystites,manganese doped products are obtained through doping of precursor liquid.The influences of preparation temperature and Mn²⁺/Pb²⁺ratio on the luminescence properties of products are studied.The results show that higher reaction temperature and larger Mn²⁺/Pb²⁺ratio can promote doping.Then,doping was carried out by ion substitution method to study the effect of reaction time on the product and analyze its mechanism.The results showed that a longer substitution time could promote doping and improve luminescence efficiency without changing the structure of perovskite.Adding PbBr₂ and PbI₂ in different proportions to prepare mixed halide perovskite CsPbI_x Br_3-x,and obtaining CsPbX₃ nanocrystres with different fluorescence wavelengths,which can cover the visible light region of530nm-750nm.