(Ca,Me)La_4Si_3O_(13):Eu^(3+)(Me=Sr,Ba)荧光粉的结构和发光特性

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

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)。

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_Eu^3＋ to n_La^3＋ in the phosphor is 1：7 and the intensity ratio of emission transition ^5D_0-^7F_2 to ^5D_0-^7F_1 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）.