Study Of Photoluminescence Properties And Thermal Effect Of Rare Earth Co-doped NaLuF₄Nanocrystals

Due to its special electronic configuration, Rare earth elements has many othermaterials that are not excellent optical, electrical and magnetic characteristics.Especially in recent decades, rare earth elements was praised as "the vitamin ofmodern industry" as widely used in various fields. In recent years, Research onfluoride has aroused wide attention of researchers, Especially NaLuF₄this moreefficient transformation matrix, become more transformation research hot spot. Inthis paper,we aim at the fluoride NaLuF₄, On conversion fluorescence enhancement,Fluorescence temperature measurement applications, develop systematic research.First Yb³⁺/Tm³⁺codeped hexagonal NaLuF₄nanocrystals were fabricated viachanging dosage of oleic acid and sodium hydroxide using a Oil heating method.Studied influence of the reaction kettle, reaction temperature and dosage of sodiumfluoride for transformation in fluorescence intensity. And the concentration of rareearth doping was optimized. By Oil heating method, we obtain NaLuF₄:Yb³⁺/Tm³⁺(Er³⁺) nanocrystals, analysis fluorescence spectrum in order to get the mostsuitable reaction temperature190℃, further combining with sample of X raydiffraction analysis （XRD） and other data, analysis of the effects of reactiontemperature on the size of the nanometer material. Under the fixed Yb³⁺ionsconcentration was25%, Tm3+ions in the optimization of the concentration is1%,When fixed Tm³⁺ion concentration was1%, Change the concentration of Yb³⁺from0to60%, conversion to absorb photons on a significant changes in the numericalvalue of n, analysis of the reasons for such changes. Joined in doped with the rareearth (Y³⁺, Gd³⁺), found in a doping concentration of luminescence enhancement, tostudy the enhancement mechanism. With the increase of doping concentration, thechange of the luminous intensity, further proves that compared with NaGdF4andNaYF4, NaLuF₄is a matrix with high luminous efficiency.Prepared NaLuF₄:Er³⁺/Yb³⁺nanocrystalline through oil heating method,Analysis the influence of doped rare earth Yb³⁺and Er³⁺concentration on theluminous intensity, the perspective of energy level on the conversion process isanalyzed. Under the fixed Yb³⁺ions concentration was20%, Er³⁺ions in theoptimization of the concentration is1.5%, When fixed Er³⁺ion concentration was 1.5%, Change the concentration of Yb³⁺from0to98.5%found strong greenspectrum emitted by samples introduced into a red light, color output control isrealized, analyze the possible conversion channel, build mode on energy conversionmodel. Based on the steady-state rate equations for the sample switch, green and redfluorescence intensity ratio and Yb³⁺doped concentration relationship are analyzed.Combination of rate equation and boltzmann distribution of samples，match theconversion relationship between the fluorescence intensity and doped concentrationof Yb³⁺.Test the influence of Yb³⁺doped with different concentration for the intensityof fluorescence upconversion. Measured the relationship of the two greenfluorescence peak ratio （FIR） with the temperature at constant power. With theimprovement of the doping concentration of Yb³⁺, fluorescence peak ratio andtemperature have different relations, expression of FIR is derived with thetemperature and the expression of sensitivity is derived with the temperature.Sample of the tablet and soluble in cyclohexane for low temperature measurements.Study the relations of temperature sensitivity and concentration of Yb³⁺codoped.Found the strongest sensitivity and application of the temperature by dopingconcentration of the Yb³⁺was60%.