Study On Nitriding Modification And Photoelectric Properties Of Commercial Tricolor Green Phosphors

The luminescence efficiency and thermal stability of some phosphors are relatively poor.But nitriding technology can effectively improve the performance of existing phosphors.The excellent performance of phosphors after nitriding is mainly reflected in the more stable space structure.It has good thermal stability and excellent luminescent properties.The commercial powder Ce_0.67Tb_0.33MgAl₁₁O₁₉ phosphors were used as a new type of aluminate series phosphors.It shows a good luminescence efficiency and can be effectively excited in the range of blue light or purple light,but the luminescence efficiency needs to be improved and the luminescence color is relatively single.Fluorescent spectral properties of commercial powder Ce_0.67Tb_0.33MgAl₁₁O₁₉ and LaMgAl₁₁O₁₉ phosphors are regulated by ion co-doping technology.The main research results are as follows:（1）N₄Si₃ and Li₂CO₃ were doped into the Ce_0.67Tb_0.33MgAl₁₁O₁₉ matrix by means by high temperature solid phase method.The phase（XRD）and EDS analysis of the sample showed that N₄Si₃ and Li⁺were doped into the cell.Both N₄Si₃ and Li⁺promote and inhibit the growth of some crystal surfaces,so that the luminous intensity of each sample,the attenuation rate of the fluorescence lifetime,the color temperature K,and the color index Ra will differ,but it doesn’t affect the peak of each emission spectrum.In the thermal stability test of samples,the luminescence intensity of each sample increases with the increase of temperature.（2）It is hoped that the related properties of Ce_0.67Tb_0.33MgAl₁₁O₁₉ matrix can be further studied with the LaMgAl₁₁O₁₉ phosphor.Since LaMgAl₁₁O₁₉ Phosphor itself does not emit any light,the luminescent ions Ce³⁺,Tb³⁺ single doping and double doping into LaMgAl₁₁O₁₉ Matrix and nitrided,After the nitriding process was by XRD analysis showed that nitriding could caused the crystal cells to produce different degrees of vacancies but reduced the appearance of impurity phases.From the spectrum of Ce³⁺ single-doped nitrided matrix that under the action of external crystal field,the energy levels of Ce³⁺ ions are easy to split,resulting in the generation of fluorescence of many different colors.The fluorescence attenuation curve shows that nitriding in the samples of Ce³⁺ and Tb³⁺ will make Ce³⁺ easily transfer energy to Tb³⁺Moreover,the luminescence intensity of the sample after nitriding is stronger than that of the sample before nitriding at high temperatures,and the light efficiency of the sample packaging lamp after nitriding is higher.（3）On the basis of La_0.2MgAl_11-xSi_3x/4O_19-3x/2N_x:0.55Ce³⁺,0.25Tb³⁺.Replace La³⁺ in the matrix according to the ratio of 3:2 and 1:1 of Eu²⁺and La³⁺.The XRD patterns of Ce³⁺,Eu²⁺and Tb³⁺doped into the matrix were investigated to infer the cause of cell volume change,and the effect of energy transfer between Ce³⁺→Eu²⁺and Ce³⁺→Tb³⁺in nitride samples was deeply analyzed.After addition Eu²⁺,the color rendering index of the sample will increase,the value of related color temperature will increase,and the thermal stability will decrease accordingly.In order to better apply to the encapsulation lamp,it is urgent to reduce the related color temperature of the sample and increase the thermal stability of the sample.