Preparation And Performance Study Of Aluminosilicate Based Phosphors For Rare Earth Doped Warm White LEDs

Aluminosilicate-based phosphors have received widespread attention because of their high chemical stability,thermal stability,and luminescence intensity.By controlling the ratio of Si⁴⁺to Al³⁺,fluorescent materials with different compositions,structures,and properties can be obtained.Based on this,this paper carried out the study of two kinds of aluminosilicate phosphors,rare earth doped Y₂Mg₂Al₂Si₂O₁₂and YSr₂Al₃Si₂O₁₂and prepared the above two phosphors with a different doping by high-temperature solid phase method to study the influence of material formulation and process on the material structure and luminescence performance.The details of the study are as follows:（1）The optimal sintering process for Y₂Mg₂Al₂Si₂O₁₂:Ce³⁺/Tb³⁺phosphor was 1350°C with a holding time of 2 h,a flux content of 7wt%Na₂CO₃,a Ce³⁺doping concentration of7at%and a Tb³⁺doping concentration of 5at%,and the excitation at 450 nm of the Y₂Mg₂Al₂Si₂O₁₂:0.07Ce³⁺phosphor emission spectrum had an emission peak at 555 nm;Ce³⁺-Tb³⁺,Ce³⁺-Mn²⁺double doping were explored,and the best combinations were found to be 7at%Ce³⁺-4at%Tb³⁺,7at%Ce³⁺-7at%Mn²⁺,respectively.The WLED package test was conducted,and its color temperature index（CCT）,and color rendering（Ra）,were 2529K,3488 K,70.4,and 75.5,respectively,with good performance.（2）The optimal sintering process for YSr₂Al₃Si₂O₁₂:Ce³⁺/Tb³⁺phosphor was 1350°C with a holding time of 2 h,a flux content of 7wt%Na₂CO₃,a Ce³⁺doping concentration of5at%and a Tb³⁺doping concentration of 3at%.Under the excitation at 450 nm,YSr₂Al₃Si₂O₁₂:0.05Ce³⁺phosphor The best luminescence intensity and emission spectrum with an emission peak at 522 nm;Ce³⁺-Tb³⁺,Ce³⁺-Mn²⁺double doping combination successfully regulated the warm white light,and the best in combination ratio was found to be 5at%Ce³⁺-4at%Tb³⁺,5at%Ce³⁺-5at%Mn²⁺,respectively.The WLED package test was conducted,and its color temperature index（CCT）,and color rendering index（Ra）,were3856 K,2782 K,71.4,74.8,respectively,with good performance.（3）The samples were sintered at the same concentration of flux,at the same temperature（1350°C）,and under the same atmosphere.In terms of crystal phase formation,both of them can form a pure crystal phase with little difference.（x=0.3323,y=0.3341）is closer to the standard positive white light CIE color coordinates（x=0.333,y=0.333）,and the color rendering index can reach more than 70,and the color temperature is lower than 3000K,which has good warm white light performances.