Spectrum Modulation Of A Single Matrix Mg_xLa_10-x-Oxyapatite Silicate Applied To White LED

In this paper,a series of single-phase multi-emitting phosphors with oxyapatite silicate structure Mg_xLa_10-x?SiO₄?₆O_3-0.5x?x=0¹?were prepared by using high temperature solid phase method and sol-gel method under low carbon reduction atmosphere,which used europium oxide and cerium oxide as activators.The crystal structure of the product was fine-tunned by the single substitution of the skeleton cation in the matrix to achieve the purpose of spectral modulation,while the crystal phase,fluorescence spectrum and fluorescence lifetime were studied.By comparing the high temperature solid phase method and sol-gel method to synthesize phosphors of La₁₀?SiO₄?₆O₃?LSO?:0.1Eu^?2+,3+?,although the sintering temperature of high temperature solid-phase method was higher than that of sol-gel method,the luminescence performance was obviously better.The effect of the concentration of europium oxide on the LSO matrix was studied by high temperature solid state method,and it was concluded that the optimum doping concentration of activator was0.075mol%.In the excitation spectrum,we could get the charge transfer band?CTB?of Eu³⁺and the 4f₇-4f₆5d₁ transition of Eu²⁺,but when excited to CTB or Eu²⁺,we could get the ⁵D_I to ⁷F_J?I=0,1,2,J=0,1,2,3,4?transition line of Eu³⁺.Through the study of LSO:0.075 Eu,it was found that under the excitation of three excitation wavelengths(?_ex=360,370,380 nm),the color coordinates are respectively?0.3907,0.3595?,?0.3472,0.3282?and?0.3504,0.3062?.Three sets of sharp peaks appeared simultaneously in excitation spectra with monitoring wavelength between 500 nm and 720 nm.It could be confirmed that there are three kinds of oxygen vacancies in the samples.The uniform distribution of oxygen vacancies could transfer energy to non radiation energy in the lattice of silicate.Adding activator of cerium oxide to LSO:0.075Eu can increase the emission spectra of blue component,which led to a relatively wide emission band,a series of green emission weak sharp peaks and a series of red emission sharp peaks.In this way,the white light emission spectrum of all light emission was obtained.A series of warm white light emission samples with low color temperature under near ultraviolet wavelength?393 nm?excitation were obtained by adding alkaline earth metal Mg²⁺partially replacing La³⁺to fine-tune the structure on the basis of LSO:0.075Eu.