Synthesis And Properties Of Alkaline-rare Earthsilicate Phosphor With Oxyapatite Structure

In this thesis, a series of phosphors Eu^2+,3+:Ca-RE-X-apatite （RE=Y, La; X=F, Cl）were synthesized by high-temperature solid state reactions in weak reductionatmosphere. Through the optimization of matrix composition and dopant concentration,to determine a suitable matrix composition and the optimum doping concentration.The single phase of multi-light color luminescent material doped with different valencestates of Eu were synthesized. The phase compositions and crystallographicparameters, the chemical state of doping ion, spectral characteristics and luminescenceproperties were studied in details by XRD, XPS, the photoluminescence excitation andemission spectra and fluorescence performance analysis，respectively. Some newregularity conclusions result from considering the substitution of the cationic andanionic components of matrix composition and matrix composition-crystalstructure-luminescence properties. The regularity of results have provided scientificreference for obtaining high performance and LED materials. The main conclusions ofthe paper are as follows:1. Phosphors Eu^2+,3+:Ca-RE-X-apatite （RE=Y, La; X=F, Cl） were pureoxyapatite phase P63/m （176） space group. The lattice parameters a, c and unit cellvolume V with the amount of X-substitution presents a good linear relationship. 2. In the phosphors Eu²⁺and Eu³⁺are coexisted. The area ratio of Eu²⁺3d5/2andEu³⁺3d5/2XPS peaks is6.9:1. The sensitization of Eu²⁺to Eu³⁺luminescence isexcellent. The intense emission lines from transitions5D71-FJ（J=0⁴） and weaker linesfrom⁵D₂level of Eu³⁺were observed in the emission spectra of exciting into Eu²⁺orcharge transfer state （CTS） of Eu³⁺, besides lines from⁵D₀level.3. The phosphors show warm white light with candlelight color, the result showedthat the substitution of Cl-is better, and the color rendering index range from75to82.5,color purity exceed80%, suitable for ordinary indoor illumination. The red ratio ofphosphor Cl=4about73.2%, and the color purity reached97.3%, available as redphosphor. The doping concentration of Eu³⁺in phosphor Eu（2+,3+）:Ca-La-Cl-apatite is0.04, the replacement of F-=0.5is more conducive to the sensitization of Eu²⁺to Eu³⁺luminescence.4. The molar ratio of Eu³⁺ion occupied in sites4f and6h of phosphor is4:6. Theemission from the high energy levels is generated from luminescent center Eu³⁺situated in4f site.