Investigation On The Synthesis And Luminescence Of Rare Earth Ions Doped Fluoride Functional Nano-Materials

The rapid ascent of nanoscience has garnered significant attention in recent years.Much of the interest generated has dealt with the integration of nanoparticles in various applications ranging from bioimaging to nanomedicine.In order for the realization of this potential,their synthesis and chemistry need to be thoroughly understood.One particularly interesting class of nanoparticles comprises a lanthanide-doped inorganic matrix.Due to their physicochemical and optical properties,these lanthanide-doped nanoparticles are undergoing widespread investigation in many fields,particularly for in vitro and in vivo imaging,as well as theranostics.Specifically,lanthanide-doped fluoride hosts are being propelled to the forefront of the current research efforts as they offer several advantages relative to other studied upconverting host materials.This review will take an in-depth look at lanthanide-doped upconverting fluoride nanoparticles' optical properties with a particular emphasis on the type,concentration and radius of lanthanide-doped,finally,the UC and down-shifting NIR properties have been studied,the processes responsible for the origin of the UC emission spectra and the variation of the UC emission intensity have been explored in detail.Herein,we selected co-precipitation in a binary solvent mixture of oleic acid and 1-octadecene to synthesize the hexagonal-phase NaYF₄:Yb³⁺,Ho³⁺ NPs,NaYF₄:Yb³⁺,Tm³⁺ NPs and NaYF₄:Yb³⁺,Er³⁺ NPs.X-ray diffraction?XRD?,scanning electron microscopy?SEM?and photoluminescence spectra?PL?were used to characterize the final products.The phases and morphologies of NaYF₄ samples have been proposed on the basis of XRD analysis and SEM investigation of the samples obtained.We exploited not only the function of dual-mode emission of?-NaYF₄: Yb³⁺,Ho³⁺/Tm³⁺/Er³⁺ NPs in the near infrared?NIR?and visible regions with single wavelength excitation at 980 nm,but also the function of physiological temperature sensing with the luminescence of Er³⁺ in the visible region.The obtained nanoparticle can be realized water-dispersible through surface coating with silica.Also,the strategy to design dual mode sensing and imaging composites maybe extended to prepare multi-functional platforms for targeted multi-mode imaging of various biological systems.Under the fixed Yb³⁺ ions concentration was 20%,the fixed Er³⁺ ions concentration was 2%.Prepared NaLnF4: 20% Yb³⁺,2% Er³⁺ nanocrystals through the same co-precipitation method,all conditions consistent in the process of the reaction.We analyzed the optical properties and characteristics of samples by SEM and PL.It can be seen that the NaLuF₄ which particles were smallest has good research prospect due to its intense green and red UC luminescence.Er³⁺/Yb³⁺co-doped NaLuF₄ nanocrystal with different Er³⁺ concentrations were prepared by the same method.The up-conversion fluorescence spectrum of the samples were measured under the 980 nm excitation.The double logarithm curve of the excitation power and the fluorescence intensity was ploted.The conversion mechanism of fluorescence was analyzed.The phenomenon of the intense green and red UC luminescence was explained by analyzing the UC mechanism of fluorescence.