The paper reports the effective control of charge transfer transitions in perovskite based titanate red emitting phosphors by site selective substitution and the resulting enhanced emission with increased colour purity. The influence of altering the substitution sites of Y³⁺ and Eu³⁺ ions at different cationic sites on local structure variations and photoluminescence properties is investigated by adopting three different protocols of composition, viz., Sr_1-x-yY_xTiO₃: yEu³⁺, Sr_1-x/2-yY_xTi_1-x/2O₃: yEu³⁺ and Sr_1-x/2-y/2Y_xTi_1-x/2-y/2O₃: yEu³⁺. It is found that optimum substitution of Y³⁺ ions at Sr²⁺ and Ti⁴⁺ sites in Sr_0.95Eu_0.05TiO₃ enhances the intensity of luminescence by 14 times, accompanied by an increase in asymmetric ratio between ⁵D₀→⁷F₂ and ⁵D₀→⁷F₁ transitions from 1 to 5.6. Further, the double site substitution of Eu³⁺ and Y³⁺ ions in this system yields emission having close resemblance with that of the commercial red phosphor, Y₂O₃:Eu³⁺ with 99.9% colour purity, asymmetric ratio 6.8 and chromaticity co-ordinates (0.66, 0.34), close to that of standard red. The biexponential luminescence decay curves propose the occurrence of two nonequivalent Eu³⁺ crystallographic sites in Sr_1-x-yY_xTiO₃: yEu³⁺ phosphors and the triple exponential behavior observed in the case of Sr_1-x/2-yY_xTi_1-x/2O₃: yEu³⁺ and Sr_1-x/2-y/2Y_xTi_1-x/2-y/2O₃: yEu³⁺ shows the occurrence of three nonequivalent Eu³⁺ crystallographic sites. The increase in local asymmetry for Sr_1-x/2-y/2Y_xTi_1-x/2-y/2O₃: yEu³⁺, which prompted the colour pure emission, compared to that of Sr_1-x/2-yY_xTi_1-x/2O₃: yEu³⁺, is evident in the increase of J-O intensity parameter (Ω₂) from 6.07 × 10⁻²⁰ to 8.98 × 10⁻²⁰ cm².

该论文报道了通过位点选择性取代有效控制钙钛矿基钛酸红色发光磷光体中电荷转移跃迁的方法，并通过提高色纯度提高了发射效率。通过采用三种不同的组成方案，即Sr _{1- xy} Y _x TiO ₃：y，研究了改变Y ³⁺和Eu ³⁺离子在不同阳离子位点上的取代位点对局部结构变化和光致发光性能的影响。Eu ³⁺，Sr _{1- x / 2- y} Y _x Ti _{1- x / 2} O₃：y Eu ³⁺和Sr _{1- x / 2- y / 2} Y _x Ti _{1- x / 2- y / 2} O ₃：y Eu ³⁺。发现在Sr _0.95 Eu _0.05 TiO ₃中Sr ²⁺和Ti ⁴⁺处Y ³⁺离子的最佳取代将发光强度提高了14倍，并伴随着⁵ D ₀ → ⁷ F之间不对称比的增加。₂和⁵ D ₀ → ⁷ F ₁从1转换为5.6。另外，在该系统中Eu ³⁺和Y ³⁺离子的双位取代产生的发射与商业红色荧光粉Y ₂ O ₃：Eu ^3+的发射近似，具有99.9％的色纯度，不对称比6.8和色度。坐标（0.66，0.34），接近标准红色。双指数发光衰减曲线表明在Sr _{1- xy} Y _x TiO ₃：y Eu ^3+中存在两个不等价的Eu ³⁺晶体学位点Sr _{1- x / 2- y} Y _x Ti _{1- x / 2} O ₃：y Eu ³⁺和Sr _{1- x / 2- y / 2} Y _x Ti _{1- x}情况下观察到的荧光粉和三重指数行为_{x / 2- y / 2} O ₃：y Eu ³⁺显示出三个非等价的Eu ³⁺晶体位点。Sr _{1- x / 2- y / 2} Y的局部不对称性的增加_x Ti _{1- x / 2- y / 2} O ₃： y Eu ³⁺，与Sr _{1- x / 2- y} Y _x Ti _{1- x / 2} O ₃： y相比，它促进了颜色的发出。的Eu ³⁺，在JO强度参数的增加（Ω是显而易见₂）从6.07×10 ^-20到8.98×10 ^-20 厘米²。