(Ca,Me)La4Si3O13:Eu3+(Me=Sr,Ba)荧光粉的结构和发光特性

采用高温固相法制备了(Ca,Me)La4Si3O13∶Eu3+(Me=Sr,Ba)系列红色荧光体,考察了Eu3+掺杂浓度和Sr2+,Ba2+置换对荧光体结构和发光特性的影响。Eu3+最佳掺杂浓度为nEu3+∶nLa3+=1∶7,5D0-7F2与5D0-7F1跃迁发射强度比为2.55。Eu3+掺杂使晶胞参数a和c呈线性变小,对c的影响大于a,使a/c比增大。Sr2+和Ba2+分别置换基质中的Ca2+可以形成完全固溶体,晶胞参数随Sr2+或Ba2+的置换量增加呈线性增大,使a/c比减小。各发射峰强度在Sr2+置换量为0.4 mol时出现极大值,但随Ba2+置换量的增加而不断增强,全置换后荧光强度最大。荧光体的色坐标为(0.638 5,0.353 0)。

Structure and Luminescence Properties of Phosphors (Ca, Me)La4Si3O13:Eu3+ (Me=Sr, Ba)

A series of phosphors (Ca, Me)La₄Si₃O₁₃:Eu³⁺ (Me=Sr, Ba) were prepared via solid-state reactions. The variations of lattice parameters and the luminescence properties were investigated based on modifying dopant concentration of Eu³⁺ and substitution amount of Ca²⁺ by Sr²⁺ or Ba²⁺ in the host. The optimal mole ratio n_Eu³⁺ to n_La³⁺ in the phosphor is 1:7 and the intensity ratio of emission transition ⁵D₀-⁷F₂ to ⁵D₀-⁷F₁ is 2.55 in the studied range. The lattice parameters a and c reduce linearly with concentrations of dopant Eu³⁺ and c is more noticeable so that a/c value increases. There are linear relationships between lattice parameters and substitution amounts of Sr²⁺ or Ba²⁺ to Ca²⁺ in host, but values of a and c increase and that of a/c decreases due to continuous solid solutions formed. The maximum of the luminescent intensities of Eu³⁺ emission appears in the sample in which the substitution amount of Sr²⁺ to Ca²⁺ is 0.4 mole per mole host, however, the intensities increase with the substitution concentrations of Ba²⁺ ions all the while,as well as a change in rate of grade at content 0.4 of Ba²⁺ ion,and the most intensity reaches till whole substitution. The CIE of the sample is (0.638 5, 0.353 0).