Synthesis And Optical Properties Of Two Kinds Of Ternary Fluoride Nanoparticles

Fluoride nanoparticles have the advantage of low phonon energy as a kind of important optical materials.The widely existence of defects in fluoride materials makes fluoride nanoparticles own the characteristics of down-conversion luminescence.Lanthanide ions doped fluoride upconversion nanoparticles have many advantages:such as high upconversion luminous efficiency,low toxicity,low light bleaching,no blinking,less damage to organism,deep biological tissue penetration depth,etc.They can be widely applied in biological field and optical fields,such as bioimaging,intelligent drug carrying,photodynamic therapy,FED,optical storage and so on.The synthesis and optical properties of two kinds of fluoride nanoparticles were studied in this paper.The systematic preparation and optical properties of K_0.3Bi_0.7F_2.4nanoparticles and lanthanide ions doped K_0.3Bi_0.7F_2.4 upconversion nanoparticles were studied.The preparation of Ba₄Yb₃F₁₇ nanoparticles and upconversion luminescence properties of lanthanide ions doped Ba₄Yb₃F₁₇ nanoparticles were also explored.The main research contents are included as follows:We studied the ultrafast preparation of K_0.3Bi_0.7F_2.4 particles and lanthanide ions doped K_0.3Bi_0.7F_2.4 upconversion nanoparticles at room temperature.Under the excitation of 375 nm,K_0.3Bi_0.7F_2.4 nanoparticles have self-luminous phenomenon.We have also explored the influence of different preparation conditions on the phase,crystal structure,morphology,size and luminescence properties of K_0.3Bi_0.7F_2.4 particles.Under the excitation of 980 nm,the variations of upconversion luminescence of K_0.3Bi_0.7F_2.4 upconversion nanoparticles with the change of Er³⁺and Tm³⁺doped ions concentration were explored.It is noteworthy that Tm³⁺ion-doped K_0.3Bi_0.7F_2.4 sample has very strong near-infrared light emission between 740 nm-840 nm under the excitation of 980 nm,which is within the scope of the"optical transmission window"of biological tissue and is suitable for deep biological tissue imaging.This ultrafast synthesis of lanthanide ions doped K_0.3Bi_0.7F_2.4 nanoparticles at room temperature,provides a new idea for the simpler and faster synthesis of fluoride upconversion nanoparticles.Ba₄Yb₃F₁₇ nanoparticles were prepared by hydrothermal method.By adjusting reaction temperature,pH and the molar ratio of raw material,the optimal experimental conditions were explored.Lanthanide ions doped Ba₄Yb₃F₁₇ upconversion nanoparticles were prepared under this optimal experimental condition.Under the excitation of 980 nm,the variations of upconversion luminescence of Ba₄Yb₃F₁₇upconversion nanoparticles with the change of Er³⁺and Tm³⁺doped ions concentration were explored.Moreover,we have tried to compound dye IR-806 with lanthanide ions doped Ba₄Yb₃F₁₇ upconversion nanoparticles,which has improved upconversion luminescence intensity greatly.Organic dye-sensitized fluoride upconversion nanoparticles provide a new direction and feasibility for solving the performance limitation caused by extremely weak and narrowband near-infrared absorption of lanthanide ions.