The Preparation And Properties Of Upconversion Luminescent Materials NaYF₄Doped With Rare-earth

Upconversion luminescent materials NaYF₄doped with rare-earth, whichpossesses the advantages of high luminescent efficiency and excellent stability, havebeen widely applied in the fields of detection and anti-counterfeiting,three-dimensional flat-panel displays, solar cells and biomedicine. It attracted theresearch interest of scientists at home and abroad. In this paper, upconversionluminescent materials NaYF₄doped with rare-earth were prepared by hydrothermalways. The influence of the hydrothermal times, the dosage of sodium tartrate,activator, sensitizer and ammonium fluoride on the luminescent properties of thetarget product were investigated by means of single factor experiments. Based on thesingle factor experiments, we optimized the preparation condition by orthogonalexperiment. The targeted products using different complexing agent were prepared onthe optimized preparation condition, and characterized with X-ray diffraction,scanning electron microscope, and fluorescence spectrum analysis. The main researchwork includes the following three aspects.（1） The upconversion luminescent materials NaYF₄:Yb³⁺,Er³⁺were obtained byhydrothermal ways. Based on the single factor experiments, we optimized thepreparation condition by orthogonal experiment. The optimal preparation conditionswere with the sodium tartrate/RE as1.25, the sensitizer dosage as18%, the dosage ofammonium fluoride/RE as11, the hydrothermal times12h. The experimental resultsshowed that the emission peaks of the products using sodium tartrate as complexingagent were located at410nm、520nm、542nm and655nm, the strongest emissionpeak was located at520nm and the fluorescence was green. The crystal form ofproduct using tartaric acid and citric acid as complexing agent was hexagonal,consisting of the sphere with100nm diameter.（2） The upconversion luminescent materials NaYF34:Yb+,Tm³⁺were obtained byhydrothermal ways. Based on the single factor experiments, we optimized thepreparation condition by orthogonal experiment. The optimal preparation conditionswere with the sodium tartrate/RE as0.5, the sensitizer dosage as23%, the dosage ofammonium fluoride/RE as11, the hydrothermal times13h. The experimental resultsshowed that the emission peaks of the products using sodium tartrate as complexingagent were located at345nm、361nm、452nm and477nm, the strongest emission peak was located at520nm and the fluorescence was blue. The crystal form ofproduct using tartaric acid and citric acid as complexing agent was hexagonal,consisting of the sphere with100nm diameter.（3） The upconversion luminescent materials NaYF3+4:Yb,Ho³⁺were obtained byhydrothermal ways. Based on the single factor experiments, we optimized thepreparation condition by orthogonal experiment. The optimal preparation conditionswere with the sodium tartrate/RE as1.25, the activator dosage as1.5%, the dosage ofammonium fluoride/RE as11, the hydrothermal times7h. The experimental resultsshowed that the emission peak of the products using sodium tartrate as complexingagent was located at542nm and the fluorescence was green. The crystal form ofproduct using tartaric acid and citric acid as complexing agent was hexagonal,consisting of the sphere with100nm diameter.